anyway, i will now flash your custom build above to see will kernel work, i don't really care about straight twrp
---------- Post added at 04:26 AM ---------- Previous post was at 04:03 AM ----------
Okay, it is finally working !!!
This is steps :
1. Flashed pixn kernel and booted into twrp(this twrp won't give error7)
2. Wipe system,data,cache,dalvik cache
3. Flashed this custom build that you posted above :
4. Flashed pico gapps
5. Rebooted phone, went through all steps.
6. Go into TWRP by fastboot booting latest zach kernel for nougat
7. Flashed kernel and this time it booted instantly
8. Again twrp by fastboot booting flashed sr3 supersu 2.79
and everything is working flawlessly.
Thanks @zacharias.maladroit !!!!
EDIT: By flashing your kernel for nougat in recovery partition Twrp can be accessed, but only by pressing volume down plus power while powering phone and then you will get yellow led(you may already know this, but this is for other people too)