I gotta say, when I heard your idea that Wally should have been the star of Flashpoint, and that the event should have been the return of Barry and the 'passing back' of the torch, I was, like, 'Oh, yes.'
Between Barry's return and Flashpoint, Wally spent a lot of time with nothing to do. And Barry's return was in the (to me) incomprehensible Final Crisis, with the explanation of 'He ran so fast before he died that he's alive now'. Or something. If Flashpoint had been the transition, both of these could have been avoided.