Well, i don't think i can answer any of the questions you asked, but i can tell you something from my own experience. I have Dish Network (which i think sometime soon is gonna buy Direct TV, so you might wanna get DISH) and my two dishes aren't affected by rain at all. Its only rained hard down here (So Cal) about twice, but both times, i didn't get signal loss.

Also, i used to sell this stuff and we'd sell them to people living in apartments, and they'd come right back the next day returning them because the managers of the apartment wouldn't let them put it up. Some places are really anal about this stuff, some it might help to ask first.