Re: Novice needing good advice for purchasing a used bowrider or deck boat
since you have water access on the bay, and as you mentioned, you aren't likely to take the whole gene pool out at once. I'd opt for quality over quantity--get a smaller boat that handles well and comfortably carries 6, rated for 8-9. 10 people on a small boat just isn't fun, and neither is a lot of tubing behind a pig.
Buy the boat for the bay, and make it fit in the lake. Look for a hull design that will handle your bay conditions. And with a boat instead of a pair of jet skis, you will likely want to fish. Therefore, avoid carpet.
Also, I see people pulling tubes/skis behind boats that are too large or the wrong design, practically speaking. It always looks like a struggle, especially teaching someone to ski or wake board, and having to constantly turn a big boat back around. Pontoons are the most ridiculous in this regard. So if watersports are a major priority, get a boat that's made for it.
I live on the water, too. it's a whole lot more fun to leave the party on the dock and come and go in the boat, taking turns tubing or whatever. You will be able to get a much nicer boat with that strategy.
BTW I took my cousin (both of us in 50's, good size) and 5 older teens (2 small girls, one medium, 2 beefy boys) tubing behind a 21' center console 150 HP 2 stroke--did fine. Might want 175 if I did it all the time. Look for something like that--very versatile family boat and made for the bay like yours. Rated for 8-9 (can't remember exactly).