Wow, I like it so much.
Part B is a great contrast to A. Much more independent lines and counterpoint than in the sketch (nice Part D).
In all, I think it's coherent, I mean it has unity as a piece, and that's important. The feeling is beautiful and contemporary. Dynamic contrasts are very good and makes it interesting.
I have a doubt perhaps more experienced people can tell us.... When there are 4 players...., rubato can be a trouble?
I will sound great in live performance!