I am not aware of US laws, but found it really interesting that the law gives absolute power to the President to even pardon himself! Can any legal expert on HN weigh in on this? Can the President really pardon himself and continue serving?
It's worth noting accepting a pardon is an explicit admission of guilt as ruled in Burdick v United States [1]
He probably could. I don't think there's anything that prevents a successfully impeached person from holding office again. It just removes them from office and requires reappointment or reelection. But I think he'd lose the popular vote again and probably the EC since enough people would've finally wised up (or just lost the momentum).
There's a related issue of whether the president can be indicted while in office. Many legal scholars say no, while others say yes, but there's nothing at all in the Consitution that says the president can't be indicted. If Trump is indicted, it will be up to him and his lawyers to make a case why the indictment should be tossed out, and it would once again fall to the Supreme Court to decide the issue. (My own, non-legal-expert view is that the Supreme Court would rule a president can indeed be indicted while in office, because, again, there's absolutely nothing in the Consitution that says he can't.)