Help ! Zte v5s n198st

I Have a Phone ZTE V5S N198ST and I can not find anything about it. only in Russian and Chinese

zte v5s n198st : 5.0 inch 1280×720 p panel IPS
snapdragon 410 64 bits * quad core 1 .2 ghz – 4x ARM Cortex- A53
4G lte – gpu adreno 306 – 2GB RAM ddr3 – 16 GB internal memory
camera 1 : 13 MP camera 2 : 5 mp f/f 2.2 – 2400 battery / 4.4 KIT KAT / SUPERSU ROOT

It is a very good terminal with a very bad rom , it is not being utilized at all its power… no available roms

this phone with android 5.0 would be nice

MY QUESTION :

1)

This telófono has 16 GB of internal memory

EXTERNAL MEMORY WITH 16GB SD

However , it has 1.8 GB for applications such as partitioned this?

2)
I can’t find roms and I recoverys , i feel afraid to try some Russian or Chinese " rom " and unable to restore unbrick

any person have this phone ? i need help thanks