Mostly related to #2, that's what most annoyed me about school-taught history. Sure, the Japanese, just for the hell of it, spend a bunch of money sending planes to Hawaii and that's how poor ol' innocent United States ended up in WWII. C'mon, why did the Japanese do it? It wasn't until years later that I learned anything about a blockade in the Pacific. I mean I can understand a little "America: fuck yeah!" attitude, but no one thought to mention that little tidbit?

The entire planet gets into a war in the early 1900s because some two-bit archduke of something-or-other got shot? WTF? Woah, back up there, Teach; you've got some explaining to do. (And when I read the explanation years later, I still go "WTF?")

Point is, if the cliche is correct then we're doomed to repeat history again and again because there seems to be little effort to explain why things happened. What the hell was the U. S. doing in some dot on the map in Southeast Asia in the 60s? Domino theory? C'mon, I doubt anyone believed that even at the time if a ten-year old version of myself is saying, "how dumb do you think I am?"

But, as you mention, it would seem that there's little enough time to teach the timeline, let alone explain the treaty situation of early 1900s Europe such that WWI makes sense.