If you don't do a clam bake,
I say keep it fairly simple with lots of variety. Do several different proteins(including some fish) and just do a million different ways to eat them -corn or flour tortillas, different breads/buns, flatbreads, pita, etc. And a ton of different toppings-salsas from spicy to sweet, crema, tsatziki, relish, chow-chow, cheeses, slaws, greens. Use your badass knives to do all sorts of knife-heavy prepped stuff!
Sides: Tomato/feta/h2oMelon-with fresh mint is great. You're a New England guy, so I know you do some good baked beans. Black bean salad with grilled corn, big chopped salad, quinoa tabouli, lentil salad, slaw(s),etc.
Variety is usually king in my line of work. It just depends on your crowd and how adventurous they are. Always keep with the seasons and it will feel like the
4th no matter what you're having.
I wish more people would send you some ideas, that way you could just do a mishmash of kkf ideas!