I imagined I had given some thought to these subjects, but Permutation City did have new ideas. If you slow down a simulation to some ridiculous degree, the simulated beings don't notice. Even if you run the simulation backwards or in random order, they wouldn't notice. If you abruptly shut it down, they'll just continue finding the pattern somewhere.
I would guess not. See Permutation City by Greg Egan for lots of speculation about questions like that.