So I'm feeling rebellious and was thinking about making a Orc character who fights for the Stormcloaks. If you have ever playing as a non-Nord Stormcloak, what were your reasons for joining them and not the Imperials? and how does your character feel about the Empire?

I once had an idea for an Altmer scholar, who fleed to Skyrim as he was being prosecuted by the Thalmor for his controversial beliefs about the Daedra. He was caught on the border of Skyrim by the Imperials, under the orders of the Thalmor. He joined the Stormcloaks to he drive the Empire and the Thalmor out of Skyrim.

It's simple, the Wimperials are weak and need to be crushed

Orcs have strongholds in Skyrim so you could be fighting to keep the Empire from taking control of them.

It makes sense for any race to help Skyrim if they want Skyrim to be free from Imperial control.

Doesn't make any sense if that character wants to live in Skyrim afterwards, though. If Ulfric wins, Skyrim is for the Nords. If you're not driven out then you'll be forced to live in squalor like the Dunmer of the Grey Quarter.

Or you could be 1 of the smart Dunmer that own land and farms right outside the walls of Windhelm

I had a Dunmer who lived in the grey quarter because her family did nothing to help themselves. She joined the Stormcloaks to earn the Nords respect, then got out of the grey quarter, moved in Hjerim and finally became friends with Rolff... after a "friendly" fight.

Hope you never need the city guard or anything.

I was all like, "If I join you will I get to kill the English Imperials?" and they were like 'Aye!" and I was like "'Kay!"