Is it difficult to sail/set up?
No. Easy to sail & very easy to set up
If I have have the boat moored on a beach with a 10foot slope down to the beach is it hard to pull out of water on a set of wheels? .
If the hill is not too steep it should not be a problem. Waves are pretty light weight and one person can move them on wheels with out any problem.
is it easy to disassemble mast to place into a uhaul?
Yes, A Wave can breakdown easily and was made to do so. If you plan to do that often get the standard version Wave not the Club Edition so you don't have to lace the tramp every time.
Waves are fun boats w/o much hassle. You will enjoy it.