Your steps to freedom...
Download viper xl 3.2.3 to your computer (for now then you can switch roms)
Connect your phone via usb to your comp Go into twrp mount your storage and drag the Rom over to the phone where you'll be able to find it on your sd
Now go into the wipe menu in twrp select wipe system and factory reset..
Nowclicj on install in twrp find viper where you put in on your sd and click on and flash it
You now have a custom Rom/root/ fixed phone
Another question, after I flash this Rom, would I be able to reset everything back to the way it was? No Root, relock the bootloader, and reset the the main factory rom?