The commendation system as it is isn't bad, there is barely anything what you can really do to change it. It will nice to allow to give commendation to somebody who already left the duty, though. Sometimes I want to commend a member but they leave like in very 1st second after kill.

As for Mentorship system, in terms of commendations I think it should have separate system connected with Novice Network, where Sprout (and only Sprout) player can commend a Mentor they liked. The more likes Mentor has, the higher their grade. For what you can use grades and how to show that Mentor is high ranked is another story but at least it will somehow show that this Mentor is probably will help you since his grade is high. But this goes only to chat helps. The idea with separate commendations for Mentors in duty is good, too.