what about having the first thread created by the user to go through moderation before it appears on the site? once you have an approved thread, you're allowed to start new threads without passing moderation. this approach works well for wordpress comments in my experience.

this gives the moderator a chance to
- give a personal welcome to the new tmo member
- prevent duplicate threads from being started
- all in all give good advice on the specific issue, should it not seem to be a good idea for a new thread to be created.
- and also, even if the thread is perfectly fine, the moderator could send a generic welcome dm to confirm approval, including good tips and tricks for tmo.