Yes, and appreciated they all are. I'm going to give the man a chance and direct any and all complaints to my (very supportive) instructor. He's not local and is very, very good about making himself the bad guy to my students to allow me to save face.
Ethan
First off I commend you for teaching at a young age, believe me I wish I started teaching at your age, instead I had just started in the martial arts.
Here is the reason I commented on this board and I believe Carol's post that Ethan is 19 years old and a fairly new instructor.
Is your instructor a daily part of your school? I mean is he handling part of the teaching duties, meeting parents, etc. etc. etc. or are you the person with the most interaction with the students?
Because if you are the one who is doing the most teaching, if your name is on the lease, if you are the one that parents are looking towards teaching and molding their kids, or trusting their sons and daughters to, or if you are the one that adults are coming to learn from then you should be the one making the decision whether this guys trains or not at your school. Even if it is a satellite or branch school, held at a Rec. Center or teaching through a Parks and Recreation Center, if you are the head instructor at that location you will be held responsible, both in the students, parents and ultimately in the laws eyes (I believe). Your head instructor should be consulted he can give you insight, but it is in your hands if you are on the front line (so to speak).
Look at it this way. If this guy or anyone else did something really bad, say he intentionally wanting to try out his BJJ arm bar lock, acts on his own and breaks a students arm, it could even be accidental, but he breaks the arm none the less. How would you feel? Would it tear you up that you he hurt another student, possibly intentionally? Or would you shrug your shoulders and say "Well my instructor cleared him, it's not my fault" when having to deal with the other student, or their parents, or the insurance company. How would you feel if later you found out from some other instructors he had done that before at another school etc. etc.
Ultimately I believe anyone who is an instructor in that type of situation will feel responsible if one of their students is hurt and there was something you could have done to prevent it. That being said, I get concerned when I read things like "I'll leave it up to my teacher", "I won't take his money until then and give him a trial period while my instructor makes the call. That's my "solution"," "Its out of my hands now and I hope it works out for him, maybe I can help". When I say I get concerned I mean for you OK? It sounds to me like you are leaving whether or not he trains at your school in your classes (or whatever) up to a third person, when I believe you should have a direct say in the matter. I also believe that you have a direct responsibility to vet the guy (or any student for that matter) in all ways possible up to and including checking out his former instructors, in order to safe guard your current students. Your instructor (and I mean no disrespect here) won't have the same concerns for your students as you do (assuming he is not actively teaching in your school and they are your primary students), no hide behind his Gi or belt rank allowing him to make the choice you need to do it.