Granular permissions for questions

Request for more granular control over questions permissions. Rather than a single 'Can Use' customer would like to be able to define groups that can view, comment and vote on questions, but not ask or answer.

Public FAQ would be one use case for this.

See comments:https://confluence.atlassian.com/display/QUESTIONS/Permissions?focusedCommentId=462716960#comment-462716960

I was wondering if there's a way to limit the number of features a (logged in) user can have.
E.g. to allow only: reading , voting and commenting q&s? (everything apart from sumbitting own questions and answering ones)

To be more specific: I'd need to have two user groups (none of them can by anonymous). The first one (an active one) should have permission to post questions, answer, vote, comment etc.
The other one (let's call it - passive) should be given only access to view questions/answers and vote/comment them.
I'm aware this is closer to classic faq solution, but was wondering if using "Confluence Questions" may be a benefit here OR it would be more wise to leverage pure Confluence pages.