Plenty of places in Ballater for food, the Glenaden Hotel is dog friendly so it would be your best bet if you wanted to sit in somewhere. Lots of takeaways around if you dont.
I seen someone park basically 1 minute drive from the main car park
https://goo.gl/maps/wvUpphTq3N1AQaVFA which avoids the parking charges, otherwise you could just park at Ballater and drive the last strech in the morning.
Seems like the snow has cleared right now but it looks like a cold week coming so I would expect snow and ice by the end of the week.