I too am dreading not having a car - but we always waste time getting lost - especially in the dark!
The transportation issue is going to be difficult because you want to eat at resort hotels, and eating at the Pepper Market would mean taking a bus from one of the parks or downtown disney, to Coronado, then back again afterwards and to your hotel. You could get a taxi, but the money you spend on taxi fares could diminish any savings you've made by not having a car.
If it was me, I would cost out the difference between staying at Coronado and renting a car.