I would do at least 2 days in the magic kingdom and then 1 Epcot 1 Hollywood and 1 at animal kingdom. The other day I would leave as a rest / hotel day
You'll be able to change her fast pass using the app or an in park kiosk. Only problem will be dealing with what's left and making it fit into your schedule. You'll also have to change one adults fast passes to suit. Rider swap will still work.
My son and nephew also did it from the grand Floridian. From what I understand it's more or less the same from all the different ports so I would pick the one that's easiest to get to. They both loved it. Would definitely recommend it.
Definitely BLT. We loved being able to walk to MK. The monorail was also amazing. We felt the pool at beach club was actually too much for our young kids. Bay lake is our favorite!
My vote would be chef mickeys. We love it there! Another option would be play and done at Hollywood and vine but that's at Hollywood studios. Have fun!