Even if you joined the Imperials, you can switch sides by doing the Jagged Crown quest, delivering the crown to the Stormcloaks. However if you've already completed it in favour of the Imperials, then there's no way to switch sides.
Imperials are better, they are trying to set up a government while the stormcloaks are starting a war they can't win
The last mission for the Imperial side of the civil war questline, is to assault and capture Windhelm, and kill Ulfric Stormcloak.
Factions you can join: Companions College of Winterhold Dark Brotherhood Stormcloaks Imperials With the Dawnguard DLC: Volkihar Vampires Dawnguard
No. I was a stormcloak and wanted to join imperials. so i went to general Tullius and I couldn't join. All he says is that he wants whiterun back :/
Sarnia Imperials was created in 1928.
Imperials Football Club ended in 1897.
El Centro Imperials was created in 1947.
El Centro Imperials ended in 1952.
Palm Beach Imperials was created in 2006.
Imperials Football Club was created in 1892.
If you mean the high king, yes I believe that you can side with the stormcloaks and then you kill the leader of the imperials and Ulfric is like oh I don't want to be high king, so in effect you can become high king.
Unfortunately skyrim itself is not multiplayer but there are mods out there attempting to make it that way