RE: Den Chief must be first class...
I must be the source of this urban legend. But I never tell anyone that it is a BSA policy. I am the cubmaster, and I will not approve any boy who is not first class as a den chief.
Frankly, though, I really don't want a first class scout, either. I prefer the den chief be an eagle scout, quartermaster, or ranger. If they are in OA and have gone through YLT, that's who I want. The more Boy Scout I can get, the better.
11 year old tenderfoot scouts do not make good den chiefs. They are just big cub scouts and their service is usually of little use to the den leader. Serving the den leader and helping them find a boy scout to assist them and guide cub scouts is my job. Providing Jimmy with a den chief cord is not my job.
The den chief position is a huge deal in a pack. When staffed with a really strong scout, like someone who used to be the SPL of his troop and is too young to be an ASM, it turns arts and crafts dens into hiking, camping, knot tying scouting dens.