I flashed system.img and boot.img and I seemed to have lost root (still on 4.4).
I booted into TWRP and tried to flash 4.4.2 but it says:
verifying current system...
Not enough free space on /system to apply patch
E: Error executing updater binary in zip ' /sdcard...
Error flashing zip '/sdcard/ROM Toolbox/[the 4.4.2 file name here]
Updating partition details....
E: Unable to mount ' /cache'
I have 5g free on my phone, that should be ample space for a 50mb update?
EDIT: Also "Unfortunately, Google Play Store has stopped" keeps popping up and the app store force closes constantly