One thing I enjoy about high school baseball in Iowa is that it doesn't start until May 20th; no freezing my nads off umpiring a game. Of course, a day in July with a heat index over 100 isn't much better. Those can be long doubleheaders (everything is a DH in Iowa HS ball).
One thing coming on these forums has taught me is that no matter how good of an umpire you might be, or what part of the country you work in, or what level you work, there are always going to be coaches, players and fans who think you suck and got things wrong. It's comforting to know I'm not alone.
On your ejections, I've never had a kid make contact with me; was that a first for you too? As for the AC driving around to the parking lot that doesn't surprise me at all. Often, the coaches are the most immature people on the diamond.