I'm happy to help out and would love to hear some of those ideas. Could you say more about what specifically it takes to build a forum and keep it running (what does it cost, what is the time commitment, what technical skills are necessary etc.)
You need advertisement, you need knowledgeable, active people, and after you reach a certain size you don't need, but should have, someone with technological skills. The first is so that people know you exist and where to find you. The second is so that people will stay after they find you. The third helps with aesthetics, security, and things like that. The second takes the most time. I was probably burning at least five hours a day on here after Scott died. It got better after a while, but the fact is that most people aren't interested in contributing to forums. They ask questions, get what they want, and leave.
Administrator-wise, be careful not to recruit all "idea people". That is part of what happened with the first forum. Between our emails and moderator forum conversations, you can find the classical theism podcast, the classical theist YouTube channel, and the classical theism Facebook group, and more, all there. (A moderator suggested the first two, but never acted on them -- in both cases within a few months other people filled those niches. We discussed and veto'd moving to Facebook partly for the reasons I've mentioned, partly because some people felt it would lower the overall level of conversation. (I supported moving to Facebook at the time, but in retrospect I think the decision to not move was right.))
I also agree that we need to decide what the purpose of the forum is. How broad should the focus be? It could be very specific (e.g. Thomistic scholarship), somewhat specific (e.g. classical theism), less specific (e.g. Christian philosophy), or very general (e.g. philosophy of religion). My vote would be classical theism, since the more general forums already exist and going more specific could limit membership (we are already having trouble getting people to post as it is).
I'm inclined to think that classical theism sites succeed
in spite of their names. It's too much of a philosophical term of art. Nobody outside certain narrow parts of philosophy even knows what "classical theism" is. It also doesn't give you much to work with in terms of specific aesthetics (if you ever want to, e.g., build a website, or make the forum look a bit nicer).
If you're going to go broad, I recommend theism, not classical theism. Everybody knows what theism is, and you might get some interesting internecine disputes with neo-theists on a theism forum.
If you're going to go a bit more specific, go with scholastic. If you go with "Thomistic scholarship", you're going to have to compete with the Thomism Discussion Group on Facebook, and that is a competition you'll lose. (Most of the professional philosophers who are also Thomists are active on the Thomism Discussion Group, and it has thousands of members.) Besides, other scholastics (e.g. Scotus and Bonaventure) are at least as interesting as Thomas. As far as I'm concerned, some of them are also right about more (e.g. Scotus).
It also gives some wiggle room on all sides: if you are really into Thomas or Scotus, or Feser or Hart, you're in the right place. But even if you are an "open theist" or just someone interested in theism in general, you are still close enough to the subject matter to join in.
Too much wiggle room, I think, and too much of the wrong kind. Relevant comments in this thread:
https://classicaltheism.createaforum.com/philosophy/the-necessity-of-creation-revisited/msg72/#msg72Sorry for the slapdash reply. No time for proper writing!