Read the letters HERE.
LW1: Wow. A bit harsh, but probably something to this. For a woman accused of being a man-hater, Prudie was kind of extreme, no? I do think she could give similar advice to a guy. I think guys have an easier time of it because women look at qualities other than appearance (to a degree), but even more because they have better imaginations about what the guy could look like after a bit of fixing up. Women like fixer-uppers, men don't (unless they're Christian Troy or the Jimmy Stewart character in Vertigo).
LW2: SIL didn't get the holiday spirit message, apparently. (She may be happy not to have to deal with this: maybe she's such a bad hostess because she's been saddled with doing Thanksgiving.)
LW3: Hmmm. The right thing to do is to denounce this, of course. But it sounds like that puts ou out of a job pretty quick. Is that important? Can you find another job easily? If so, feel free to do the right thing. If not, you may wish to keep your mouth shut. That should keep you in your job for a while at least. My personal opinion is that if you really think the boss is not aware of his wife's dealings, you should take it to him. I think there are ways of doing this without making it an accusation of his wife. "Gee, Dr. Smith, I was wondering about this bill. It says that L'il Jimmy got a root canal, so should I schedule a follow up visit?" If the cheating stops, that may be the best way to keep yourself employed.
LW4: Solution: breath control, dear!