As for the Jarls, there are good and bad Jarls of both factions. So regardless of which side you decide to help win the war, the provinces of Skyrim will end up with a mixed bunch of Jarls.
Anyone else feel like they could have added in a 3rd (more difficult) option which allows you to choose a High-King yourself among the Jarls and pick who becomes Jarl in each province? Among a few options, at least 1 of them being a "good" Jarl. Would feel more satisfying to me, even though it sounds a bit cliche.
Right now I can't bring myself to finish the Civil War quest, I feel bad killing Ulfric and I also feel bad finishing off the Imperials. So the plan right now is to either ignore the quest or do the Imperial ones until I get to Riften and then stop (preventing Maven from becoming Jarl). Does this have any negative effect on the main storylines?