Why can't wewe go into the imperial gaurd places even though wewe are know as the Champion and still can't be in guard bartracks and stuff like that?

do wewe mean champion of the arena?

Because thats how it is no matter what wewe do they wont allow it but on some occasions the guards don't ask me to leave at all!!!

If wewe mean the Imperial Palace and the other areas like Ocato's room wewe have to do the Theives Guild quest but if wewe mean the reagular Barracks then idk but wewe can illigaly ^_^

I think because the politics of the monarchy,the kings au Septims are at the juu so they have the
ability to use the whole tower floor 1-5,Ocato 1-3,you 1-2.

because wewe are just a fighter not a guard

I dont know probably its A glitch au something xD