>>1359488>>1359491I've only been to moosilauke, but the tops are were everybody congregates, so it wouldn't be ideal. And all of the available info for the area says you need to be a few hundred feet from working trails, and a few hundred feet from bodies of water too. Not like the rangers will be out there every day, but just to be safe, and respectful.
I'm not sure about swimming holes, but I can almost guarantee you theres a few good ones up there. Do a little research, and you'll find many stories. Try to follow and you might just find one.