Dear Kedusha,
Yeah. I agree with you, but wanted to kind of talk about it within the "realities on the ground" perspective, that's all. Besides, you and others here are more knowledgeable about the actual halocha than I am.
Dear shomerbris,
Ervah - the private body parts that typically "turn others (usually guys) on". Torah says that refers to all skin that he wants us to cover with clothing. Biblically, this refers specifically to genitalia. With one's wife, the normally covered skin is not referred to as 'an erva', except in the context of saying Sh'ma, brachos, and Torah stuff. On the other hand, anyone who is considered halachically prohibited for one to marry (or be sexual with in any way) is loosely referred to as "an erva" to him or her, too. And that would include shiksas, another Jew's wife, your mother, your father, etc. It's confusing, no?
Mistaber - "sensible", "likely" or "probable" (from Shprintza-Feigah's Yinglish Dictionary for Lakewood Police Officers, tofshinlamedaleph [goyish 1971])
Hora'as sho'oh - something that may normally be prohibited by halocha - but under special circumstances allowed just one time or for a single person (like Eliyahu betting on an open miracle at mount Carmel [my personally favorite mountain flavor]). It may also refer to the prohibition of something that is normally permitted, but as that's not that much fun, they don't talk about that as much in the literature ;D