I don't know what the residency requirements are under Florida law. In Texas, if you are a resident on election day, you are good to go. Some states may have no inter district residency laws. But even if legal, if someone parachutes in, then the carpet bagger issue is out there.
It would be nice if Jeb was designated the nominee. He could hold the seat for the Republicans, and he only has about 5 more weeks in office. I think he would do a great job in the House too.