Does Bill have permission to slip you vague facts about your previous self or world?: Sure.
Is there anything specific you would like him to focus on?:
Her actual name, Stephen's Ward, various anatomy stuff.
Can Bill mention any random details of your world to someone else? : Sure. Lotsa taxidermy and dark Victoriana things.
Is there anything you absolutely do NOT want him to know: The ACTUAL GOREY details of the anatomy stuff, all the other horrid shit.