Well that was what I was suggesting, using another "stock" rom, to fall back on if you ever needed it.
If you're wanting to check out other Roms, I'd suggest Jellybam (make sure you download version 4.0 or 4.1- version 5+ have issues).. and don't forget, viper is the only rom that will flash boot.img for you, so if you are switching:
Reboot to recovery> make a back up of viper, then reboot system.
Once you are booted back into viper> open flash GUI and flash the next rom.zip you want.
Now reboot to recovery, go to wipe, and factory reset.
Back out to the main menu of twrp recovery after the factory reset>install new rom.zip... and it should boot fine.
With jellybam, there is an animation issue with the boot animation, don't be alarmed when it flashes white every other second... if after 8 minutes or so, if you are not booted into the rom, force a reboot by holding the power button down until the screen turns off... it should boot at this point.. if not, go back into recovery and wipe + reinstall