Facebook Foibles

I'm new to Facebook, so I don't understand all of the little nuances, but I can already see that the whole Facebook experience is going to present some problems for me.
For instance, I am friends with a lot of people on Facebook who I really don't even know. Sometimes they put something interesting up there, and I am compelled to comment. But, when I do, I'm sure they're saying, "Who the hell is this person?" "I'm a friend of a friend of a friend of a friend of a friend....." is how I want to reply, sounding even dumber and making the situation even more ludicrous.
Then, I have all these people asking me to be their friends, yet I don't know them. I see their friend request, and I let it sit a few days, and then I feel guilty and say "Okay. I'll be your friend." But, I know nothing about them and usually just end up looking at their baby pictures or photos of their kids spewing food or their grandma making what looks like either a jello mold or moonshine. What's the point?
And then all my friends invite me to do all of these stupid, time-wasting things on Facebook, like take an IQ test, or play Internet poker, or hunt for ducks (what is that all about?). I have no desire to do any of these things! Don't these people work? I hope they don't think I'm being rude by not responding. I don't dare hit the "Ignore" tab, because if there's anything worse than saying no, it's ignoring someone. People hate that. It's like not returning a phone call, essentially.
Then, sometimesI get curious about one of my so-called new Facebook "friends" and start looking for their stuff. Pretty soon, I know a lot about this individual, yet they know nothing about me. Recently, I was at a party when such a person entered the room. I casually walked up to her and told her that I was on her Facebook and then began outlining all of the things we had in common, obviously information I had gleaned via Facebook.
"I went to San Jose State just like you, I have a dog and I used to be a standup comic...etc...etc." To say she freaked out is an understatement. She could not get away from me fast enough! "I'm just trying to be nice," I said to myself. It wasn't like I was hitting on her...or was it?
Then I realized--Oh my God--she probably thinks I'm a Facebook Stalker!
Then there's the re-finding of old friends on Facebook. I have found that aspect of the site to be very overrated. A few friends have tracked me down, and at first I was kind of excited. Until I talked to them and realized that time changes everything. They were stranger; different from before and eventually the communication tapered off and disappeared altogether. Whoever said that you can never go back was right!
Facebook can be fun. But, it can also be very confusing. Once I learn the ground rules, I can see that it might have some value to me. But, right now, I'm just a Facebook newbie; an adolescent to the site, you might say. I'm going through that acne, braces, puberty stage in the world of Facebook, but soon I will be a pro at it. In the meantime, however, the whole thing can be rather awkward at times.