In my suggestion, they will not be barred from participating in the forum, they will continue to enjoy the posting pattern as they are doing currently.
It has nothing to do with moderation or appointment of mods, as being implemented on other forums. Mods are and will continue to be appointed as per present policy, it will NOT be the sale of MOD position.
3.It happens everywhere, who pays more gets more previliges, go to Nadra pay extra to get fast track option, go by air using the business class by paying extra, go for watching cricket for free (or with less amount) or pay extra to go VIP enclosure, in train pay extra and get the AC class or sleeper class, so why not on Pak Wheels?
those car less or bike less will continue to get registered in the same way they are doing presently, it will NOT be like kick out all those who cannot pay.
It is a website / forum not the charity organization 
Unions and creation of any such organizations will lead towards the ban
(kidding).
I hope i have clarified all your points, still you have any queries, i am at your service 