"I believe you are talking about content rating, but this problem is an even more to the ground problem. Kinda a fundamental one. 

I think the problem is in the infrastructure itself. The most basic low-level stuff of how peers can know where to connect to beforehand to get certain data.

in this case: how does Alice even find bob and his content every day, in a decentralized unstructured (or minimal) manner?"

above is the quoted question that needs to be solved. Try to break up the problem in different parts. Satoshi Nakamoto solved it. Can you too?