LP--
I largely concur with your sentiments. In fact, many associated with the EF-JFKA have died off, and the remaining often reminisce about the 1960s, which is still the defining decade in all history, in their view.
Like Larry Hancock, I conclude the WC and FBI generally followed President LBJ's instructions that nothing be found out about the JFKA that could trigger a nuke war. That is to say, no leads back to Havana or Moscow.
That may seem farfetched today, but in 1962 the US very nearly went to a nuke war with Russia over Cuba. LBJ, like everybody else, lived with the daily specter of A-bombs from the sky in October 1962 (as did myself).
Due to my read of the Z-film, I contend that the cadence of shots cannot be explained by a lone gunsel armed with a single-shot-per-bolt-action rifle.
I suspect LHO was the TSBD shooter, but there had to be another shooter too.
The conspiracy could be that, only two people.
LHO was dead with 48 hours, and his confederate---who knows?
If LHO's confederate was waxed by G2-DGI, dead men tell no tales. And the people waxing the second gunsel did not know why they perped the deed, or they were misinformed.
Indeed, G2-DGI'ers may have suspected one of their assets went rogue and worked with LHO, and so they then waxed that asset, based on a reasonable suspicion.
One sad aspect of this: Moscow and IRGC $ has warped JFKA narratives, as understood by many.