For example, maybe I'd like to have a forum where I could invite heavy hitter wholesalers to discuss niche lists, marketing strategies, etc., but don't want every eyeball out there having access.

You can find upcoming local REI group meetups here https://www.biggerpockets.com/forums/521-events-and-happenings

@Mindy Jensen  I absolutely LOVE BP and have listened to every single podcast, not to mention spending a lot of time in the forums.  

Happy Thanksgiving BP Forums!

You should also dissect BP forums and blogs to get more detailed information on your niche. 

In some cities, it's easy to work with and in others its more difficult.Since you are new to Bigger Pockets, it would help you to know you can search for previous forum discussions about any topic. 

Lastly, I want to promise BP to set aside my shyness and be much more involved in the Forums.

I'm totally new to investing, and to the BP forums, and have learned more in the last 30 minutes from a couple of post than I ever could have imagined I would.

No one in this forum is going to be answer conclusively either so your best bet is to speak with  a local zoning lawyer and also to the zoning officer in town in detail. 

I don't spend much time on Forums, but my nephew has recommended Biggerpockets to me as a real estate agent who would like to experiment more actively with investment.