Virtus, I would suggest against making people register as entrants to the club. Finding seven players online, that have already pre-registered, isn't too likely (especially not near the beginning). Anyone who is currently online and reads inside the thread that a game is forming may opt to join, understanding the rules.
Speaking of the rules, here are my suggestions:
NMR Spring 01: Cancel
CD in 01-02: Draw (some may disagree with this, but we need a way to prove there was a CD and prove who was the person who CDed if we're going to ban them from our club.
03 and later: Player discretion, with the caveat that one shouldn't try for the solo if they would not have gotten it if not for a CD (We're trying to form a group of like-minded players. Taking advantage of CDs is against what we're trying to do here.)
So, the way this typically worked was someone would post in the thread if they wanted to get a game going. People would communicate in the post. If seven players are found, then someone will make the game, and PM the link, password, and a full list of participants in the game (it's important that all seven players know who their 6 opponents are, not just the person who created the game, to prevent any unfair advantage).
What might be a good idea is for someone to also post the game link and list of participants in the forum after it gets underway (or after it's finished?). It would be useful/neat to have a place where those games are documented in case of any dispute, or simply to come back at some time in the future and see all the previous club games.
You opted to take the reigns on this, so the decision is up to you, but these are my suggestions.