So it is clear for my situation, when I decided to give Nui a go, I deleted my Interface and WTF folders. Ran repair.exe checked all the boxes there, and click 'Reset Only'.
Then followed Nui's install instructions to the T.
So I should be clean with the install.
More testing to do, but for some reason I do not leave 30 FPS at windowed mode. 60 FPS in full screen mode.
25 man's disconnect at some point.
10 man's are ok
40 man Alterac Valley raid are ok.
