Strange setup question...

[LMB]

If I purchase and setup a XenForo forum with a wordpress domain, in order to create a paid membership group, can I:

1. Send my free 'seed' group there with the proper URL(in other words, just tell them the URL, not with a landing page or anything complicated),
   
2. Have them enter their own email/ID/Passwords
   
3. Close the forum to New members until I decide if it's working, etc...
   
4. If I decide it's working and I want to give my 'seed' group a major discount for joining,
   
5. Can I then have the 'seed' group rejoin and continue to find new members? Or am I overcomplicating the crap out of this?
   

6 I know that I'll eventually have to set this up with Samcart/Stripe, etc. to have it all done automatically, but I'm just starting...
Thanks!