I am a total newb...
 

Ok so I downloaded a couple of interface pieces and put same ui on all my characters... Well for some reason it crashes me on only 1 particular character, how do I go back to default on that one while keeping the ui on the rest?

Not possible at this time.

Delete that character's ui settings file. That cures most problems of this nature.

(EQ2 base dir)/(server)_(character)_eq2_uisettings.ini