That's fine; the resort parking is for guests while they are enjoying the amenities of that resort, be it dining, shopping, looking around, etc. There have been occasional reports of guests not being allowed to self park at the MK resorts when it's really busy without an ADR. So if you are there during one of those times, the guards at the gate will let you know, but in most cases, you should be okay.
Regarding the Dole Whip, I thought Captain Cooks stopped carrying it when the Pineapple Lanai location opened.