Thanks for the detailed writeup, although I prefer booting from an .img instead of the partition. This way I can just reflash boot and have my Android back
By the way, I saw that you are struggling with the bluetooth as well. Did you make any progress there (assuming that karin has the same bcrm43... as suzuran)? I believe (might be totally wrong) that Bluedroid is located pretty deep in the kernel, and you cannot really get access from the outside (meaning that this is a kernel issue). I never found what to (back)port from other devices to make it work, though.