I agree with tartansail. You might want to consider going up to P-town if you really want to people-watch, or go to Block Island -- that's a real scene. Also, Jamestown has a few nice restaurants that have their own scene.
Another thing to mention is if you go to Cuttyhunk it will probably be too crowded to find a mooring
inside, and don't even think of anchoring
outside in the "bight" if there's a norther or T-storm in the forecast
I would avoid any of those crowded places on a holiday week but then I'm an old married guy who likes it quiet.