I had to Odin back to stock (this also includes re-rooting and reinstalling TWRP) and set my mobile network mode back to LTE/CDMA. I wouldn't call anything safe yet, especially AOSP or anything non-TouchWiz or even TouchWiz stuff ported from other devices until you start seeing some stuff built for our device, HLTEVZW (SM-N900V). If you must play around, I recommend looking for ROMs that work for Sprint devices, HLTESPR (SM-N900P), which is the closest CDMA device to ours.
It looks like development for the hltevzw stopped in CM11. I'm looking at building CM12.1 for our device starting with the hltespr as a start. CM 13 isn't officially supported for that device either yet so I'm not looking at that yet. If I can get 12.1 running without much issue I'll look into CM 13. So far I'm stumbling just getting a decent build environment running and don't have a lot of time.