Is there an easy way to restrict permission for a role so that user in this role can only view Discussions opened by him?

He should be able to post in categories and open topics as normal, but only be able to see and participate in the discussion started by him.

On a similar topic, could it be done vice-versa. That a role is able to see all the discussions as normal, but only see his answers in the discussion, and cannot start a discussion.

So, kind of a one way: One set of users should be able to start "private" discussions, as "questions", and not be able to participate in them, and another set of users should be able to see these "questions", post answers, but not see other people's answers.

I mean I'll dig through the code and do it with million of bugs, but if someone knows an elegant solution, using existing permission system, it would be great.