Nice. Your Cha project has the beginnings of a search engine with cosine similarity, even though I don't think you intend to take it there. Tagged items are like a precomputed inverted index, and the matching is a search on that index.
Yep! I'm not planning on working further on Cha at the moment, but I've learnt a lot since I initially wrote the PoC code and that is probably how I'd go about it.
