Personally I think Facebook is invaluable.
There are so many people I met and worked with when I was living in Canada for a couple of years, most of which I would have totally lost touch with, aside from the odd e-mail every year. With Facebook, despite being the other side of the world, I can still be in contact with such people and see what everyone has been up to.
It's kind of hard to remember what it was like before Facebook now.
I've got to admit I'm doing less and less posting of status updates, perhaps also because I'm using Twitter these days.
As for the OP, I think an employer trying to add you as a friend on Facebook before even giving you a job is a bit weird, it's certainly not proper practice and I'd blame the person hiring you for that one.
Also, I don't know how long ago it was that you canceled your account, but Facebook have been moving away from where they were in terms of having tons of apps and clutter that annoy you. In order to give everyone a clean, standardized main page, more or less like what they started out with. Infact, any app boxes on your main page will soon be removed.
You can also now hide, permanently, any app news story that appears in your news feed, such as Farmville, so you never have to see it again.