For what it's worth, we have a similar situation arriving just a bit earlier but at the Swan before we check into the GF for the week. We do NOT have park tickets for that day. We've considered the following:
Big River Grille-Seems to be the most casual, has decent food/beer, and the outside tables are supposed to have a great view of the board walk
Beaches and Cream- Dependent on getting an ADR 60 days out (probably unlikely given we won't have the +10 option)
Ale and Compass/Lounge- While the full service variety requires an ADR, think the lounge might be a bit more open
Il Mulano-Probably the best food, but we're just not sure if we want something this fancy on arrival day