there should be someone to control that if a player gets free lessons that same player gives free lessons. . .
It's impossible to control that. Teaching ladder that i think about would be based on peoples willing to help weaker players. It's obvious that at some point help from stronger ones will be very rare as they will have no time or they will take money for lessons.
So... No control just a group of friendly people willing to help others.
I am just pointing to the problem. . .yesterday i wached open seeks and there were about 20-25 of them 80% put that they want to play only with players that are rated higher than they are. . .so if "Teaching ladder" starts it will have the same problem. . . there should be someone to control that if a player gets free lessons that same player gives free lessons. . .