Re: should there be an age for black belts?
I do agree that a black belt should be a certain age. In the AWA the is an age requiement, but if you test befor the age of like 16 or 18 i don't remember exactly, you still can't wear a hokama.
I also believe that the uper ranks should work with the lower ranks. If the lower ranks only work with each other the ability to learn will be depleted, there is only some mutch that they can gain from working together. In my old judo school it was that way, if you wanted to work with a higher rank you had to practicly run them down because they thought we were not wirth the time. From my own training I have learned working with those lower then me helps my technique. In my jujitsu and my aikido school, it is said that you don't really start to understand the techniques until you have to try to teach them. I learn something new every time I have to teach a technique. I don't know about your style, but our black belt test is the colored belt requierments with a few extras added on. You must show that you understand the macanics of the techniques you are doing, and do them with kemei and good ty sobaki.
However I don't think a child under the age of 13 should even be allowed to think about testing for black belt.