Restrictions for usergroups?

[SD40T-2]

Pardon me if this sounds off the wall....

First,
What I'm wanting to do is restrict certain user groups from being able to post links (URL) and (IMG) image links. This could be in any forum or a PM. I don't want to necessarily want to block links from a forum for all users but rather the opposite; block a certain user group from posting links (in BBcode) completely. I don't want to completely block all BBcode, just URL and IMG links for say, regular members. A higher authority of user group would be allowed. Can this be done or am I off center.....?

Second,
My other concern is the ability to control PM's. What I want to do is restrict who users can send and receive PM's to and from. Let's assume that I have three levels of users (simplicity for sake of the conversation - I intend to have a lot more); Administrators, Premium members and regular users. In short, what I want to do is allow all to receive messages from the administrators. Premium members would be able to Private message each other and administrators but not regular users and regular users would only be able to PM with Administrators and no one else.

I'm not certain if this type of complexity is possible but I'd like to know what control can be had without cutting off Admin PM but at a minimum restricting all other PM capability for a certain usergroup.

Any help would be appreciated,

'Dee'