If you are going to stay at WDW, I'd do OKW. It's less points and will be easier in and out to I-4 if you know how to get there. My first question though is why use your points at all. Why not just stay somewhere off site, maybe in the area you're visiting. For your trip I'd do KSC first and stay in that area for the night before. Travel to Tampa area the evening. Then get 2 nights in the Tampa area near BG. That way if you decide to spend the third day there, you'll be all set. With your plan, you're looking at spending more than 2 hours per day on the road. If you then want to hit WDW, you could do so for a lessor amount of time.
With my suggestions you will spend the same amount of time on the road for one day each and save maybe more than 2 hours on the third day at BG if you decide to do it. BUT you'll be traveling at what would be more convenient times and would be far more rested in the long run. Good luck.