When a fuse goes bad, stuff doesn't act weird, it just stop working. When a MFS goes bad (or starts failing, semantics...) weird stuff can happen. There's so many connections within that switch that i've seen interior lights come on when someone tried turning fog lights on.... or to get the high beams to work they had to hold the lever at a special angle.

Granted im not a fan of just throwing parts at vehicles... but if all of your fuses are good and those are your symptoms, i personally would throw a MFS in there. $60 from rockauto...