First up, if say Wishes starts at 9, what time should I make a res. to be there for the fireworks?
We went about 1.5 hours before wishes and we were set at a table that was not next to a window but had a good view. If you want a window seat your best chance is even earlier.
Do most people go out on the balcony to watch the fireworks and then come back in?
We have went out on the balcony as well, the view is much better there but IMHO I would rather enjoy dessert and watch it at a window. Plus like another poster mentioned it gets windy.
What about at tables by the windows?
see above
And about the food... I was thinking of just ordering sushi. Is that ok?
We like sushi and have found that the fare here is good quality. We had the snake in the grass and a tempura roll of some sort both were delicious. Another place for good sushi that never seems to be busy is the Kimonos at the Swan and Dolphin. If you are a sushi fan I think you should try that place out too.