Which actors would be good to cast for which npcs?

Some ideas:

Ralof - Chris hemsworth
Emperor - Brian Cranston
M'aiq the liar - Steve buscemi
Ondolemar - tom hiddleston
Jon battleborn - Owen wilson
Ulfric storm cloak - Colin farrel
Isran - Michael jai white
Jarl baalgruf - Sean Connery
Heimskrs - billy connolly

nah Ulfric could be played by non other then his VA actor I'd wager.

Did you just cast Colin Farrell as Ulfric Stormcloak?

I think he did.

I also have a hard time seeing him as Ulfric..

Mel Gibson would be a better bet, still crappy though.. haha

Ulfric - Liam Neeson