No they will not ban you for using any addons.  They are not 'mods' at all.  They run using the built-in api's that Blizz has made available to developers. 

Any addon that works is "legal."  You may read about old addons that no longer work (think decursive and some functions in healbot) because Blizz removed the api's that they didn't want people to use to automate certain parts of gameplay.