I'd read them once and maybe more if you have time. Realistically, you won't benefit much by reading them twice but it might help a bit.
Some questions are quite simple. Stuff like which courts hear which types of cases, how long you have to file various things, and so on. Not much thinking involved.
Others are quite stupid. You might have a PR question where you have a problem and the question consists of choosing which of the four things you should probably do should be done first.
Nope, we didn't receive any emails about the option of reconsidering our acceptances. I believe students still have the opportunity to withdraw their acceptances at any time if there are any concerns but the school itself hasn't given that option to accepted students