I always find the resort hotels to be very useful, esp. at Disney & Universal, as you can get access to the parks before the general public on certain days. I do this schlep/holiday annually and probably wouldn't ever stay off site.
As far as flights are concerned, I've never done TPA onto Orlando, but have no issues with arriving into MCO anymore (especially as the CBP queues are much faster than they used to be) and have also done MIA then an AA dom to MCO for a cheaper fare than direct to MCO. Just make sure you have plenty of time to clear CBP in MIA.