The basic events are "a particle moves from one place to another place" and "a particle is emitted or absorbed", and the amplitude or these events is "e" to the power of "i" times the "action" for this event
Is that like the idea that a particle being in a certain position has an amplitude? It doesn't. The universe does. It's just that if you pretended that a decohered particle was its own universe, you'd get the same results from much simpler calculations.
This does explain why physicists tend to write amplitude as a complex number. I've wondered that for a while.
Timeless physics is what you end up with if you take MWI, assume the universe is a standing wave, and remove the extraneous variables. From what I understand, for the most part you can take a standing wave and add a time-reversed version, you end up with a standing wave that only uses real numbers. The problem with this is that the universe isn't quite time symmetric.
If I ignore that complex numbers ever were used in quantum physics, it seems unlikely that complex numbers is the correct solution. Is there another one? Should I be reversing charge and parity as well as time when I make the standing real-only wave?