My opinion:
Reviews should not be optional. If photos go unverified for more than 1 week, they will be removed from profile until verified.
Escorts should also be able to review clients, if they have a forum profile. The review of clients would only be visible to the client in question and the escorts.
Before being able to leave a review, the profile must be 1 week old, have at least 10 posts and a neutral or positive reputation - the reputation feature should matter, it could also help reduce trolls on the forum.
You wont know, until you try!