Since most Class C offenses are under original jurisdiction of JP or muni. court; if a kid is charged with a Class B or above in Juvenile court, can he plea and be adjudicated to a lesser-included Class C in Juvenile court?

In prior threads there was a split opinion from two lawyers that I consider top notch on this issue, so I defer to them; but, in your situation if everyone is in agreement I would reduce it to a Class C and then have the JP/Muni court do a discretionary transfer. This scenario works as long as the class c offense is not a traffic offense. If the class c you are considering will be traffic, then it just needs to be sent down.

If a defense attorney asked me to reduce to a class C - I would tell him no, because the juvenile court does not have jurisdiction (with some very narrow exceptions). I would try to work out something - perhaps you could put the child into a diversion program - deferred prosecution - if he completed successfully, then he would have no juvenile adjudication and would be eligible for immediate sealing of his record(at the court's discretion, of course.)