If for example you choose the magic user class are you then stuck with wearing robes? I completed a quest and the reward was a "jacket" which when I equipped it displayed as a robe. Not a huge problem in the grand scheme of things but for those of us with fashion conscious characters it is of vital importance

This http://tamrielfoundry.com/2013/10/skill-overview-armor/may be of assistance to you. You can wear any armor as any class or race, the only restrictions is how you want to do it. If you obtain something that looks like a robe but don't like robes? Well then don't wear it.