I know what you mean, and your theory is actually good... but there is one thing not *. If changing Paige's death made change his memory, then he should have known, too, that Wyatt wasn't saved yet, when he went through the portal in the finale.
********* ********* ********* (Wyatt, Tory und Kyle (und Jason) im German-RS)
Yeah. You know what I wish we can do? Get Brad Kern on here to explain to us fully of what was really going on and we would ask him why he confused us so much. LOL cause its true. Now you see I wish they had us fans write the scripts. But maybe....he covered up the thing about Paige dying cause remember in Spin City when he said about how in the future she provided him money? Unless if she was a ghost or something which that'd be kind of weird.
I might know why he didn't realize that Wy was saved. Perhaps Gideon covered it up and that he pretended as if Wyatt was saved so he made them think that and so Chris thought he had done it. But if only they had Chris and Leo go into the actual future and find out it wasn't saved it would've been much better but then that is another boo boo they made.
Well actually if you think about it, Chris changed Paige dieing during the Titans thing so his memories of her would have changed to. So he would have grown up with her so the slip in Spin City wasn't really that bad.
The book couldn't be removed from the house by evil but good can take it from the house. That's why Paige could throw it out the window and Phoebe's premonition in season 1 showed her taking the book out of the house and giving it to the shape shifters, how the shape shifters could touch it i don't know but thats how it left the house.