Tried to update again completly for 2B06 and AGAIN, it failed at 83/100.
Nothing I could do to restart from there... either wrong version, so rebooted the phone, and now get IMEI read failure to install the update.
So back to square one: phone unrooted, lots of chinese apps, no google apps, no IMEI, no recovery, need to restart from scratch and understand what's the hell with the failure at 83/100. I suspect something wrong with the replaced file RF.ZTE. I'll give a try with the original version and manually root/install the recovery myself.