Well, in order...
1a) I seldom write yaoi scenes, but when I do I keep in mind that, just because they are having a homoerotic moment there is NOTHING else different. Gay people are like everyone else, all shapes and sizes. Then I look over at my friends brother (who is gay) and realize that the 'skinny girly' yaoi is way overdone. However if they are trying to do a 'feminization' item then all that is good lol.
1b) I usually ignore it in others writings. Their styles and thoughts are their own. If I had a problem with it, I'd simply stop reading and leave a review telling them why I stopped reading.
2a) A lot of writers see it in anime and other movies and don't realize how traumatic these scenarios can be. However, with some writers they take that into account and make the person go made later in a story.
2b) I ease my char's into the homoerotic situations as I would with a straight situation: passion, embarrassment and pure curiosity.
2c) I don't see to much wrong with these scenarios, as I said to each their own and if they don't want to read about it, they wouldn't be or would just stop reading.