I studied a bit of Egyptian religion in a comparative religion course. It fascinates me and I always wanted to learn more.
One, rather stupid, question - what do you call the ancient egyptian religion? The instructor never told us and now that I think about it, I'm curious.
One thing to note - Egyptian beliefs on the afterlife changed often during their multi-millenia period. I believe, at one point, there were three 'souls'. The Ka, the Ba, and another one that I can't remember.
I think it would persist without 'me'.
I thought Osiris did the weighing.
Personally, since I'm being weighed against Ma'at, I'd send flowers and candies before hand. I'd also invest in the book of the dead.
As to Ammit - there were (at least) two schools of thought:
1. He would devour you whole. You are screwed.
2. He would devour the bad half of you.
Depending on which is true (or a third?) would depend on what I would try to bribe him with.
I'm not sure what the shabti are.
I'm not getting the reference...It's been a while.
I'd guess 'yes'.