You state "for now invites can't be send Because they have been reached their user limit."
This is not true.

New members can only get in through invites or an interview. For invite you'd need to know some power user and up, for interview you'd need to give at least a good elevator pitch on why'd you'd make a good addition to the cgpeers

This was quoted from their IRC chat.

Also, if they are unable to invite someone, they should ask CGPeers staff for some help by visiting their IRC.

I hope you can correct it 👍