"What needs to be done to prevent this proposal from stagnating?"
I'm not going to mince words -- the description practically guarantees that it will stagnate!
The major problem is the phrase "committed Buddhists". Here are a couple of specific issues with it: how do you define "committed Buddhist? How do you define just plain "Buddhist"? Why exclude someone who is not yet a "committed Buddhist" (in whatever sense you like) but is considering becoming one, and is using the SE area to help make that decision; Etc.
Apart from these specifics, aren't there people who have a lot to contribute, especially in terms of questions, but are not themselves committed Buddhists in any sense of the term? I believe that SE thrives because it's open to and attracts people on the basis of the quality of their contributions, not on who they are in "real life". You don't have to be a committed mathematician, philosopher, whatever to ask good questions or give good answers on the corresponding SE area.
The other problem is the blatant typo in the description, which belies the care, energy and commitment needed to execute a successful proposal.
Until these problems are addressed, I am personally reluctant to devote any more energy to the proposal than this post. Well, I will renew my suggestion for a better description, namely...
"For student and practitioners, present and potential, of any type of Buddhism, for questions about Buddhist philosophy, teaching, practice, history and relation to the modern world."
Apologies if I am indirectly criticizing the author of this proposal, but having failed once, at least in part because of an inadvisable description (the emphasis on monks, IMHO), I think another failure would be fatal, if the patient is not already dead.