No luck on finding global firmware, or finding TWRP for this phone, but here's a quick guide I assembled for rooting the ZUI firmware:
Important: Make sure to...
face unlock also supported?
It seems to work fine, I have only personally tried face unlock in HavocOS. You may need to enable Smart Lock under Trust agents, in Security and Location settings. Also, if you go with Havoc, make sure to flash the ...
sounds great.. are there any bugs with this custom rom? preferable to stock rom?
No MTP unless you boot into recovery, but RR and HavocOS are both good choices in my opinion.