Yes, there are multiple terminals, but they're all like spokes on a wheel, so you don't have to take buses or trains to get from one to the other.

On the subject of our flights, I researched, and there are really no other acceptable options. I looked back at our original flights, and the new one is only 15 minutes later than the original, but they've allowed 30 minutes more flight time than the flight normally takes, so I think we'll probably be fine. If we miss the connection, there's a later CLT/SXM flight that's showing a lot of empty seats now; so we've decided to stick with what we have for now. I'll keep my eye on the seats on that later flight, and if they start to fill up, we'll decide if we want to go ahead and book that flight, or just take the chance.

Oh the joys of flying these days.....not.