This would be a powerful DAC, that could have huge potential if done right. You should have feedback from people who have taken classes with various teachers, that way people can see how good they are at their skills. One idea which has been central to Bitcoin is the idea that the system is trustworthy because you don't have to trust any individual, just the whole system. Here, you don't have that, since you have to trust the teacher. However, if you were able to have feedback and references accessible to everyone, then you could spread the trust out a bit more.