We were there last year, and it was crowded starting the 2nd. Since this year the 4th is on a Sunday, instead of a Friday, and everyone has the 5th off, I don't know if you will see more crowds after the 4th or before the 4th. I'm guessing it will be split. Definitely the 3rd and 4th will be packed in the parks, crowds will probably lighten a little on the 5th and will be much better the rest of the week.
As far as the resorts, we stayed at the Dolphin and didn't notice it being too packed at the pool or restaurants but it's a HUGE resort.