OMG...you will love this resort! The YC/BC are my favs!!! You don't have to worry about buses to MGM or Epcot because you can walk to them or take the boat. When going to Epcot, I would suggest walking...VERY short. MGM is a little longer, if you can catch the boat right away it would be the fastest; however, we many times prefer the walk...it's so peaceful!
The buses to everywhere else aren't bad. You will share a bus with Swan, Dolphin, Boardwalk and Yacht club. I know that it sounds like a lot but they are all so close together it only takes about 10 minutes to make it to all the stops. Many times, on the bus ride home you won't have to stop at the Swan or Dolphin.
Enjoy your stay...it will be so magical, I'm sure!!!