If you're still using Facebook, it's because you're required to or you're the kind of person who won't be fazed by this.
Marketplace. It's horrible, but the area I live in has mostly abandoned craigslist and if you want to buy/sell used stuff, marketplace is where you have to be.
Correct, for better or worse facebook is the meeting ground for many communities and if you are in those communities you have to use it.