We have basically the same last day as OP (staying at BWI, departing around 2pm).
I have been trying to get a breakfast ressie at Crystal Palace, but that isn't happening. Without that, we can't justify the schlep to and from MK. We will most likely walk to Epcot & spend our time there. We're foodies, so we will always welcome one more opportunity to try a new restaurant in the WS. Also DD loves all things Japanese, and will want to make sure she has not overlooked any souvenirs in Japan. After 7 days in the parks, we will have done all the major attractions, so it will be nice to be able to just putter around and revisit the things we really enjoy.