I've got way too much going on here I could fry my whole system and I need this PC to last me another 3 years at least. So I decide to take out some of the more extensive Mods namely Redhawk's "Revan the White" (sorry but I've got work on this computer that I can't loose) I don't know where you dot that idea but mods won't break your system. At most they will be incompatible with each other and they will mess your game but you can uninstall them at any time, load a prior save game and everything is back to normal. They don't affect other applications than the game itself.
I have no problems downloading the usm mod from pcgm. Try with another browser and if it doesn't work, it could be your internet connection. You can also download it from our website:
http://www.starwarsknights.com/kotor2mods.php)
In Kotor 2, you can make subfolders but I don't recommend it to anyone who is not familiar with mod conflicts as they make conflict detection even harder. You can use KMM to help you get out of this mess. Otherwise, check the files included in the original .zip or .rar file of the mod to identify which files go with what. Sometimes authors list the files in their readme too.