En Masse can't really ban since the GPK's will just fail a CRC check only on certain patch updates. Sure they 'could' put a check for modded GPK's and immediately ban all of those with modded files, but it would kill a part of the user-base. For now, they only ban those that post pictures on the official forums, and there's a possibility they could ban on-sight in the game if the GM's see a mention of it from a player. Though so far, I've been lucky to not get caught in LFG or Global when talking about it, so.. maybe its because its after hours perhaps, or just real luck.
Only reason now I don't use uMod anymore is because I don't like putting my graphics to 1 and I hex edit similar armor appearances now. All I can suggest is for the use of uMod, you start uMod first, or TERA, can't remember right off the top of my head... Then you load the game (if uMod was started first), get into the game itself, minimize and load the DDS textures you want. Update/refresh and go back in the game and toggle graphic settings between 2 and 1, or 0 if you must. It should eventually show if you have the correct armor equipped.