When you say …"someone" waiting at 1026 I assume you mean law enforcement? Do you think they would park outside or be waiting at the gate? However we know Earlene told of a police car outside while Oswald was getting his jacket. If it was the real reason why not just stop a block down the road when the coast was clear. Every minute counted it seems.
But Earlene wasn’t saying that on the day of the assassination, nor the next day, nor the next day. Only about a week later, after a week of having police cars parked by the house from time to time, did she suddenly remember seeing a police car parked near the house on November 22.
As for lack of preparation I wonder why he spent Wednesday night until midnight at the washerteria across the road from the roominghouse and had to be asked to leave. If he was going to "do the deed" on Friday, why take $13 or so? Not enough for an escape and too much if caught/killed in the act.
What preparation could he do with the rifle at Ruth Paine’s house? Any preparation can’t start until Thursday night. Might as well get his clothes clean for Friday.
Another one of those what if’s as an aside for the LN crew. Lovelady and Frazier were friendly. They quite often helped each other when their cars needed assistance, charging etc. Lovelady lived in Irving and his car was not operational that Friday he had to take the bus. Can you imagine Frazier saying to Oswald that they were giving him a lift too? Lovelady getting in the back seat with a package?
I imagine Oswald would insist on getting in the back so Lovelady, who had known Fraizer longer, could sit up front with his friend.