Question(s):
1. How will you be dealing with the water buildup around the outside of your pool that will collect there every rainfall? (mosquito breeding ground and probably not very good for the life of the pool)
2. Where on the east coast - will you incurr freezing/frost? If so, your pool WILL heave because the saturated clay from above will expand drastically.

Now back to your questions...

You should not have any issues compacting the filled in clay, I had my grade for the pool raised 2 feet, let that sit over the winter to settle, then got final grading done in spring. I also used about 4" of screenings as a sub base for the wall, compacted these screenings with a gas plate compactor and it never moved or settled at all.
The compactor will do a good enough job, remember that the pressure a full pool exerts on one square inch is less than 2 pounds or about 270lbs/sq foot, that's less than a person standing on the same ground/sq ft.