Bigcrit:
Your schedule seems pretty fixed and park oriented. You may not need a car.
For me tho,I'd NEVER be w/o a car at WDW. As an example, our first day: check-in at OKW, validate AP at guest relations in DD, (do some shopping there), back to Fantasia gardens for mini golf, back to OKW for a quick swim, then to Narcoosee for dinner.