I didn't read the thread and don't know your exact layout or needs. This is just my dream home layout...
Get rid of as many walls parallel to the beach inside. The ultimate would be one long 20 ft wide corridor from exterior land-side wall to floor-to-ceiling beach-side windows (or better, sliding doors). In this tube, if you had the kitchen land-side, a dining table in the middle, and a couch and wall-mount TV (perpendicular) beach-side, you'll have easy ability to break out folding tables and chairs for 30 and just as easy of a time whipping out air mattresses for 6-10. No matter what, you'll see the water cooking, eating, and relaxing and this is especially handy if you're working inside but supervising those outside. If there's almost no furniture and the floor is a darker wood, you'll also have a super-clean modern design and only need a vacuum to clean.
I love open air but hate screen doors (especially since they're hard to see and easy to break). If you're able to have a rail around an inch off the floor, I'd use floor-to-ceiling sheers wrapped around both floor and above-door rods. It'd be less bug-resistant than screen doors but give you that "drapes flying in the wind" feeling without a crazy infestation. You can also use sheers instead of walls.
Something like this:
I'm not joking about screen doors. They put my great uncle in the hospital because he walked into one and fell. If you have dogs running in and out, you'll want the doors open anyways.
Your living-room-to-outside doorway should open three body widths wide. Kids are going to run in and out. You're going to carry BBQ and grillin' stuff in and out. People are going to mingle. Make it big! If only my local HyVee did the same thing...
The only furniture you should have are beds, small bedside tables, chairs, tables, bathroom shelving, a place to store board games, and a couch. NO DRAWERS EXCEPT IN THE KITCHEN! The bedrooms should have a closet, a bedside table with an alarm clock, something to set a suitcase on, a lamp, a chair, and nothing else. Spare bedding should be folded in the closet. You aren't storing other clothes there so don't bother with dressers. The bathroom(s) should have an ungodly number of towel racks (put pegs in the hall for good measure). Otherwise, open exposed shelving for people to stash toiletries and not forget them! The only cabinet should be under the sink to hide cleaning supplies and toilet paper. You'll need a linen closet stuffed with a TON of both beach and normal-size towels. If there's room, you'll want all your family games and a vacuum. Otherwise, the only "stuff" left goes in the kitchen (cleaning supplies under the sink, a drawer for normal tools, and a goodly amount of dishes, a stack of paper plates, and a triple-set of silverware because you'll run out FAST and plastic forks suck).
If it's hidden, it won't get used or it'll get forgotten. Keep the clutter down so you can hit everything FAST with a damp cloth or a vacuum.
That's my minimal lifestyle prescription.