This advice is horrible for anyone who is expected to initiate sex. Good luck doing that without any sort of goal-directness.
My impression is that two people who spend enough time together and are physically attracted to one another will tend to eventually have sex. It usually takes a lot of willpower for this not to be the case.
Not if you're the sort of person who doesn't know how ordinary people go about signaling they're amenable to having sex.
It was only in retrospect after a lot of social learning that I became aware of all the times in my past that I easily could have been having sex, but wasn't because I didn't recognize the cues I was supposed to be picking up.
Clarisse Thorn recently posted a useful article about Ethical Pick-Up Artistry, bringing up a few basic critiques of traditional PUA and suggesting a few alternatives.
A proposal to formalize thisNot the same thing, but a discussion on forming a community to practice social artistry in general has been brought up on LW before, but I'm not personally aware of anything coming out of that.