Do they have any sort of live re-enactments like they do at other civil war sites and what time of year if they do?

I believe they do, maybe twice a month. At least I thought I heard or read this when I visited.

No they have a tour guide explain the history of the fort but no reenactments

Ft Sumpter does not have any re-enactments.

Yeah I don't think so. Walk around free & ask the park rangers whatever you like. And added bonus go on the first orr last for & be apart of the flag raising or lowering ceremony.

No