When you go to there profile it would not show there details, unless they have done something with there safety settings.
u dont
You annoy the hell out of someone, say something rude or mean, or make them feel really awkward. By the way, don't do any of those things :)
no
If they do not appear in the search box when you look for them, you click on their name somewhere on a friends page (say a friend lists "in a relationship with: so and so") and it redirects you to...