does anyone know if we will be able 2 buy sell or trade slaves if we join this clan and if so send me a private msg

As far as my knowledge goes I don't think it has been confirmed. But seeing that CL is a slaver group I'm sure you'll be doing some work in the slave business.

do u think that they made so that u can sell and buy slaves anytime u want or only on a mission

If it is implemented it will probably be like FO3 where you can turn slaves at anytime you like. But like I said, unconfirmed. :shrug:

Well I think all we know about CL's slaves is that they will give us quests most likely towards freeing them, but I don't think we've heard anything about trade.