is this the main Trek site?

Each individual Star Trek series has it's own page and to my knowledge, there isn't any single one that's utilized for general Star Trek discussions.

You might try commenting on the Gene Roddenberry page though. I think that's the closest to what it sounds like you're after.

Nobody posts on it! https://moviechat.org/bd0000016/Trekkers-Only

Dude, nerds are all over the site. Post wherever you like.

Just address things more or less specific to a particular series on the page for that series. The page for TOS is also a good place to bitch about how bad Trek is today...