I find facebook fantastic for keeping in touch with my friends back in Canada. For the longest time I didn't let anybody in Ireland know I had facebook as I kept is specifically for people back home.. but then my husband's cousin asked to add me :( I would have offended him if I had turned him down, and once I accepted him, the rest of them all ended up on it is as well.
I have my settings set that only certain people can see my page. People I'm not fond of, or THAT friendly with.. whom I don't want to offend by deleting as I see them regularly, are have limited access to my page. You can also switch off what updates you receive from people so that you don't have to see the rude remarks.. that is what I did when I was on the receieving end. :)