All brilliant ideas there, having Qui-Gon disappear would be difficult to work into a saga where Jedi vanishing is unheard of.

It might be seen as proof that he was onto something about Anakin but it would be difficult to reconcile with Vader's apparent WTF when Ben's body does it in ANH.

Unless in that context it becomes more of a "Oops! So he can do it too" sort of thing but Vader seems to take a lot of pride in it being Kenobi's final end and is still convinced of it in ESB (but that too could contexually change into Vader keeping more secrets from his master in the hope it will help him get the old bugger out of the way).