Yes, this sounds like something for a specific group. The largest pot luck I have attended was about 100 people, and other than making sure young children and their parents went first, before the ravenous pre-teens and teenagers, everything went smoothly. I think that if any cooking goes on during a potluck, it is in a slow cooker or warmer.
I think store bought items are okay, as long as the person does not always contribute one bag of chips and a container of dip, or two two-liter sodas (examples from work and a social club). It begins to feel like they are taking advantage for many, not my opinion, but one I have heard many times.
I find it in very poor taste to take more than one plate of food before everyone has gone through, we ended up having to approach a co-worker that wanted to make a plate for her spouse during the first pass (he doesn't work here) at every event. She is also one of the front of the line people every time.