No.

Nah, defeats the whole purpose

In light of new, previously undisclosed evidence yes.

It makes no logical sense. Legally, hopefully not because more innocent people would end up in jail.

If there is a violation of a contract’s terms, of course.

No takebacks, once you commit you should stand by your past action. It doesn't mean that you have to keep doing it.

NOPE

No. While it is happening, sure.

You can, but it's useless and mindless.

Yes..You never know for real if you're gonna like some things til you try them. It's ok to change of mind and withdraw consent so you don't have to do anything you don't like again

during, not after