The best CT alternative I could offer is that Oswald was involved with the shooter.

Oswald brought the MC rifle onto the TSBD that morning and hid it in the attached garage part just before he then went into TSBD thru the back door.

The shooter if not some other employee, would have had to been disguised as perhaps a contract worker. He retrieved the bagged disassembled rifle from where Oswald had hidden it in the annex bldg.

The shooter took the bag to the 7th floor and assembled the rifle , probably between 11:45-12:00.

The shooter then remained hidden on the 7th floor until about 12:10 when he took the assembled rifle (covered with the bag )in case he was inadvertantly seen coming down to 6th floor landing by somebody coming up stairs from 5th floor.

The shooter had checked out the 6th floor at 12:00 thinking it was clear but BRW came up unseen by the shooter at 12:05 as the shooter went back up to 7th floor to get the rifle.

When the shooter returns to the 6th floor carrying rifle in bag, he was planning to shoot from the SW window. He was surprised as he approached the SW window to notice BRW was at the SE window. Thus he was only momentarily sighted by Arnold Rowland at 12:15.

The shooter backed away from the SW window,put the  rifle back in the bag ( in case another unexpected person might appear) , moved himself with bag in hand to the NE corner of the 6th floor behind some boxes where he could wait and see if BRW would leave the floor.

The shooter saw BRW leave the floor by 12:24. The shooter then had has potentially 2-3 minutes to have arranged 3 boxes stacked as a rifle rest. The shooter was wearing gloves which is why he left no fingerprints on the boxes, the bag, and the rifle. The Oswald print on one of the boxes was merely coincidence of Oswald having  handled MANY boxes when he was helping move boxes earlier.

The shooter took the rifle out of the bag and left the bag there in the SN. He lowered the window and placed the box on the window ledge just before the Bronson film started.

The shooter sat on one box and kept himself out of sight during Bronson film and Hughes film.

The shooter hid  the MC rifle between the boxes near the staircase as early as 25 seconds post shots  because he could run faster than 8ft/sec, not having to wipe prints from rifle while running with it.

Just one question. Other than BRW showing up, is there any evidence that any of this happened?

Why do you need and alternative to the WCR narrative? OK. That's two questions.

The "war" is not costing much. Many of those are sunk costs regardless of whether they are engaged in a conflict or floating around the world.  The costs are certainly much less than the harm that Iran would cause if they were allowed to develop and use a nuclear weapon.  How much did 9/11 eventually cost us because Bill Clinton put politics ahead of taking out bin Laden when he had the chance?  I do agree, however, that the overall military budget is not sustainable.  Trump's addition is a grain of sand compared to decades long accumulation of debt.  Politicians don't want to be the bearer of bad news.  They feel as though that they can't get elected stating truths such as the socialist programs at not sustainable given all the spending.  How many billions were wasted or stolen in fraud using COVID as a pretext?  They will wait until it collapses rather than acknowledge that reforms are necessary.

Hold on. You're not calling it a war? - So, do u prefer conflict? 
  but not actual war, huh? - Fox News propaganda is very effective indeed.

The opening frame of the Darnell footage is less than 20 seconds after the headshot.
At the time of the opening frame Weigman, is filming the Hesters.
He finishes filming around 17 seconds after the headshot.
Four or five seconds into this footage we see Weigman running down the knoll to where the Newmans are.

    Nobody has detailed the route Wiegman took: (1) from the point we see him stumbling/falling on the Bell Film, to, (2) the point we see him standing at the bottom of the Knoll. Point (1) and Point (2) are Not inline. The Wiegman story has always been that he Stopped Filming when he ran Down the knoll. Now, we know that Wiegman was also Not Filming when he moved from point (1) to place him inline with point (2). This expands the Wiegman Tick/Tock. If Wiegman stumbled and then Fell as he moved into position to run down the knoll, this would be additional Tick/Tock.
     "Pictures Of The Pain" details that Wiegman saw SA Lem Johns UP the knoll. Is it during the above time frame that Wiegman saw SA Johns? Wiegman claiming to have seen SA Johns UP the knoll, is contrary to Johns claiming that he never left Elm St after jumping out of the LBJ SS Car. For its' initial 30 yrs, the Wiegman Film was ballyhooed as being filmed "continuously". Did Wiegman actually continue filming while he moved between points (1) and (2) and film SA Lem Johns UP the knoll? This possible "lost" footage would also be "lost" Tick/Tock. To this day, NBC has steadfastly refused to release the Original Wiegman film.   

...and about $8 trillion++ of that national debt belongs to Donald Trump
How much does his war in Iran cost everyday?

The "war" is not costing much. Many of those are sunk costs regardless of whether they are engaged in a conflict or floating around the world.  The costs are certainly much less than the harm that Iran would cause if they were allowed to develop and use a nuclear weapon.  How much did 9/11 eventually cost us because Bill Clinton put politics ahead of taking out bin Laden when he had the chance?  I do agree, however, that the overall military budget is not sustainable.  Trump's addition is a grain of sand compared to decades long accumulation of debt.  Politicians don't want to be the bearer of bad news.  They feel as though that they can't get elected stating truths such as the socialist programs at not sustainable given all the spending.  How many billions were wasted or stolen in fraud using COVID as a pretext?  They will wait until it collapses rather than acknowledge that reforms are necessary.

https://www.msn.com/en-us/news/other/this-is-how-the-kennedy-assassination-actually-unfolded/vi-AA24beTn?ocid=msedgntp&pc=EDBBAN&cvid=6ac3d82aee6245dfb67324114522f194&ei=17

Although the title of the above video indicates this is about the JFKA, the clown doing the narration spends most of the video talking about the history of security measures for presidential motorcades and little time on the JFKA. Only the first 45 seconds and the time from about 10:00 and 12:00 are devoted to the JFKA. During that brief time, the narrator makes several dubious statements, the most glaring is that the Secret Service should have inspected every floor of every tall building along the motorcade route. This statement is laughable on the surface. Does this bozo have any idea how much manpower would have been required to do that and how long it would have taken. And what good would that have done? Even if the Secret Service had inspected the TSBD earlier that morning, how would that have prevented Oswald from shooting JFK? The only way that would be effective is if personnel had been deployed on every floor of every tall building along the motorcade route. That literally would have taken a small army to secure every possible sniper location along the route. Not only would that have been required in Dallas, but in every other city JFK rode in a motorcade during his roughly 1000 day presidency. The claim was made by a guy who was trying to sound smart, and failing badly.

The last sentence applies perfectly to your post.

Even a newly hired Secret Service official should have realized that, if nothing else, at least the tall buildings in the plaza where the motorcade would have to slow down to make two hairpin turns needed to be checked and monitored. At a minimum, the SS should have asked Dallas police officials to have some of their officers scan the windows of the four tall buildings in Dealey Plaza as the motorcade approached the plaza and while the motorcade was moving through the plaza. This would not have required "a small army" but no more than 12 officers, with three officers assigned to scan the windows of each of the plaza's four tall buildings.

In 1963, the Secret Service routinely asked local police to scan tall buildings along motorcade routes, but this was not done in the case of the Dallas motorcade. This was one of the many suspicious deviations from SS standard procedure that occurred in Dallas. Even the WC admitted that the "usual practice" of the SS official who was in charge of security arrangements for presidential motorcades, Winston Lawson, was to ask local police to scan the windows of buildings along motorcade routes. The WC also admitted that just covering "the most obvious points of possible ambush" along the motorcade route "might well have included" the TSBD:   

Admittedly, protective measures cannot ordinarily be taken with regard to all buildings along a motorcade route. Levels of risk can be determined, however, as has been confirmed by building surveys made since the assassination for the Department of the Treasury. An attempt to cover only the most obvious points of possible ambush along the route in Dallas might well have included the Texas School Book Depository Building.

Instead of such advance precautions, the Secret Service depended in part on the efforts of local law enforcement personnel stationed along the route. In addition, Secret Service agents riding in the motorcade were trained to scan buildings as part of their general observation of the crowd of spectators. These substitute measures were of limited value. Agent Lawson was unable to state whether he had actually instructed the Dallas police to scan windows of buildings lining the motorcade route, although it was his usual practice to do so. If such instructions were in fact given, they were not effectively carried out. Television films taken of parts of the motorcade by a Dallas television station show the foot patrolmen facing the passing motorcade, and not the adjacent crowds and buildings, as the procession passed.

Three officers from the Dallas Police Department were assigned to the intersection of Elm and Houston during the morning of November 22 prior to the motorcade. All received their instructions early in the morning from Capt. P. W. Lawrence of the traffic division. . . .

Captain Lawrence was not instructed to have his men watch buildings along the motorcade route and did not mention the observation of buildings to them. The three officers confirm that their primary concern was crowd and traffic control, and that they had no opportunity to scan the windows of the Depository or any other building in the vicinity of Elm and Houston when the motorcade was passing. (Warren Report, pp. 448-449)

I take it you have not read any of Vince Palamara's research on JFK's SS protection nor watched any of his videos on the subject.

For any newcomers or silent readers, I recommend reading Palamara's book Survivor's Guilt: The Secret Service and the Failure to Protect President Kennedy. My book A Comforting Lie: The Myth That a Lone Gunman Killed President Kennedy includes a long chapter on Kennedy's inexcusably and suspiciously weak SS protection in Dallas, including numerous photos that show that in other motorcades (1) SS agents rode on the limousine's side boards and/or rear boards or walked alongside the limo and (2) local police motorcycles traveled alongside the limo, neither of which was done in Dealey Plaza.

I also recommend Palamara's video Uniquely Insecure: The Tragic Failure of the Secret Service on November 22, 1963.