First of all I think the mentor requirements are decent. They are based on very obtainable merit as they should be. Merit doesn't imply you are going to be good, rather it is objective proof you have potential to be. It should also be noted that Mentor roulette includes synced EX primals so knowing fights like Ramuh Extreme and Shiva EX, etc. will be necessary unless you plan on going in there and being like "I don't know." The inclusion of EX primals in this roulettes means it likely won't be quick and easy in and out like a dungeon roulette depending on the duty you get. Spamming fates will not teach you how to tank ramuh ex. So while I don't some people will cheese the system, acting like it is going to be the rule as opposed to the exception with no proof and without ever having used said system is a bit silly imo.

As far as trolling and people joining specifically to troll/harass, from the patch notes it seems like mentors are going to be held to a bit higher standards. In regards to the novice network for instance, kicking someone from the channel automatically triggers a customer service ticket (GM request) and outwardly talks about the revocation of mentor privileges. Harassing others is also is a violation of TOS and can lead to an account ban. Considering the relatively high necessity for Patience and time and direct interaction with GM's on infractions along with generally limited awards for using the system I doubt most people will even bother to do it beyond those who are interested.