It wouldn't be a problem getting from AK to Coronado Springs because you can just take that bus- but what hotel are you staying at? After your meal at Coronado Springs,(assuming AK is closed) you would have to take the bus to Downtown Disney, then get on the bus there to get back to your hotel.
Very time consuming.
If you have a car, take advantage of it!
Anytime we have a car at WDW we drive (with the exception of MK since you have to park so darn far away).
The last poster nailed it when they said you'd be spending massive amounts of time traveling if you took the bus. If you have a car there there's no reason not to take it--especially since there are so many signs to guide you!
It depends. Driving will always be quicker. However, when my DW and I BOTH want to have a drink or two, we have used the buses. It only works well if you want to go to a park after dinner that is open late like MK since direct buses can be picked up at CS. If you time it right, it can work.
We did not have a car last year so we took a cab to three resorts for dinner. Much quicker and didn't have to worry about timing buses, switching, etc.