Start organising games and posting gametales till the gamers get sick enough to tell us to make a tabletop community, sounds like a plan :>
Tzeentch
Queer communities in general would be good, be they for advice, memes or sharing in general, both broad queer subs and ones specifically for a given group
As Reddit moves towards becoming public the odds of them purging queer content to become "family friendly" is quite high, so making sure there's spaces ready here would be good preparation i think
Outside of that just more hobby communities in general, from sports, to gardening to card games, any hobby that doesn't fall within the traditional perview of what tech and foss bros like, so theres something worthwhile here for non techy people
Especially as one of the appeals of reddit is that it's all too easy to pop into a subreddit for any hobby and get a basic overview of where to start and an easy place to ask for questions you can't easily find, being able to replicate that to an extent would be welcome
There is a way, the Power Delete Suite script can overwrite all your comments with any message you give it, and then follow it up with mass deletion if you wish, only catch is that the original doesn't account for reddits current rate limiting and so misses stuff , but this fork of it seemed to do the trick for me
https://github.com/pkolyvas/PowerDeleteSuite