So it havve now been quite a while since I have played Oblivion and I want to get into it again. However, I will need some help with this i think, expecially when it comes to the concept of the character.

The only thing I really have is that I want to play an Imperial and that I do not want to be a stealth character. Other than that I am open for ideas on RP, archetype and background.

Hmmm, Imperial eh? The first thing that popped into my head was soldier. You could RP being a watchman, either in the Imperial City or travelling around on the roads, making them safe for the citizens of Cyrodiil. Might be a nice idea to do.

WooHoo! Battlemage (custom of course).

I'll second Acadian, and say battlemage too. Maybe RP him as a Blades auxiliary, on loan from the mages guild.