BuddyPress.org

@jmarino:
Well, there’s a plugin to restrict group creation. I’d start there: https://wordpress.org/extend/plugins/buddypress-restrict-group-creation/

In the settings, you can auto-demote group creators to mods, so that’s good for what you mention. You can also separately determine who can make a public, private or hidden group. It doesn’t have a setting to restrict somebody who meets the threshold from creating more than one group, though. You’d have to work around that. Also, it has settings like minimum number of days as a member (of your BP site in general) before qualifying to create a group, but nothing built in that’d handle maximum number of days as a mod and then demote automatically.

Honestly? You’re looking for very specific and limited functionality. Since you already plan to manually add any additional mods, I’d consider just getting the necessary info from the user when s/he signs up for VIP membership, manually creating the group in the first place (use the Restrict plugin to keep anybody but a site admin from being able to do so), inviting the VIP member to join, and then setting him/her (and any friends) as mod.

As for the 1 year demotion, I’d just use a good calendar and set up an electronic reminder.

Low tech and not very automated, but that really seems like the route you’ll end up needing to go, unless you (or someone else) wants to create a fair bit of custom code–something you probably won’t find people offering to do for free.

…

Not to be a total downer, but I’m having a bit of trouble imagining what enticement mod status would offer. Maybe I just haven’t toyed with it enough to see its utility in managing forums, but it doesn’t seem to provide much control over the group, at least…