Good news, I know what is causing the battery drain. The phone never sleeps due to bluetooth holding a wakelock. It should be possible to fix this rather easily by switching to Bluedroid. These 2 changes should help:
I'd need someone to compile a 4.2.2 ROM with the mentioned changes. Also, please don't forget to compile the ROM with the bcmdhd module.
If you need the kernel for compiling the ROM, just use this package for now:
Sent from my Nexus 4 using xda premium