I've only had my flag stolen once, and that too was at night. What I would tend to do is, find a spot where you can leave your flag, where it is out of their way and range, and dive responsibly to avoid boats.
I called the police and they came out, I got to ride around in their squad car in my wetsuit still, they talked with the person but he denied having done anything, and the officer gave me his card with his number on it to call if I ever needed anything. I was pretty mad, but at the end of the day, a flag is nothing to lose your life over, and now I focus on outsmarting them rather than fighting them.
They have just as much right to be there as you, and you don't want to get a hook caught on yourself, either, so I would try to find the places to enjoy that don't overlap with theirs. For example, hug the shoreline in shallow water, leave your flag tied to the first piling, enjoy under the bridge but not out in the open water. On the east side, swim back out in shallow water, enjoy the area under the boat docks, then reverse to exit.
The park does sometimes have sketchy people there, but so far it hasn't been a real problem. The life you see will be different than LBTS, and both are great dive sites.
I've also had some dives with just terrible viz. One was a night dive, and I called it 5 minutes in, it just wasn't fun. Enough people dive there that you can watch the Facebook group or the thread on here, and see recent reports, but you also learn that strong storms cause runoff, and can kind of predict when it'll be less than good.
I used to run a mailing list that sent out tides weekly, but that grew onerous. I still host a simple to use tide tool but mostly use the site for gas planning tools. BHB is an awesome place and I hope you get to keep enjoying the good parts.
www.divebhb.com
