1) Depends how political you are. I'm of the opinion that education should at least give people the tools to be active in democracy, even if they don't use them, so I consider at least a broad context for the big issues to be important.

2) Hard to say - I'm a history buff, so most of my knowledge is self-taught. I'd have to go back and look at notes.

3) Depends on the class. I tend to prefer the big-picture stuff, which is actually shockingly relevant to my life(not because I'm a national leader, but because I'm a strategy gamer), but there's more than enough historians who are happy to teach you about cultural dynamics and popular movements. You think popular music history might help someone who's fiddling with a bass guitar?