To remove the addon did you actually do what you said you did....

"I deleted WTF, Interface, patch.txt, and realmlist."

As in you deleted the folders WTF, Interface - if you did then this is probably why your install of wow is no longer working.

Can you retrieve these from the recycle bin? (Unlikely). otherwise I would suggest reinstalling wow.

For future reference - to remove an add on, goto the interface/addon directory and delete the folder named after the addon you want to remove.