Agh, the rooms' states resetting and recharging the amulet was a bug I thought I'd patched out - sorry it confused you and hurt the experience. Generally, the rewind mechanic is only meant to be used in rooms with the bell.
The game does have a branching story - there are technically up to five endings, though four of them are bad endings. As for how to get past the conversation with the manager that usually ends the game:
[ENORMOUS SPOILERS]
You end up having to lie and say that it was one of the patrons who told you about the vault. From there, it's just a matter of who you choose to accuse. Use your judgement, and [EXTRA BIG SPOILER] don't accuse the manager; he runs the place, and can get you arrested easily.
[/SPOILERS]
Thanks for playing the game and for your feedback!