Re: We're not sure what to call him
"Kyucho" just sounds weird. It sounds like the person would be head of a level, as if your dojo were organized into kyu, rather than people having them. "I'm a member of yonkyu."
It sounds like you want something along the lines of:
"Ano mudansha no renshu to shinsa no junbi o kantoku suru yatsu".
Again, why does this person need a title? Are you creating an official position in the dojo?