I loved the movie, I already had thought about this theory dozen of times. Watched several time related movies. Also read about it time relativity.
What I felt odd was that when Vera dies her memories die with her but instead of its shown that Vera from another time slice have the memory of Vera who died already. I didn't like it, if the director had let her be natural and not knowing the memory of Vera who already died would have been better and more realistic.
Either way it doesn't matter but Its my personal opinion that keeping it more realistic could've been great idea. Once she is dead in anytime her memory cannot be be brought back with another Vera but it shown and it irked me. That's all.
Enjoy the movie, it's easy to understand.