Facebook doesn't sell information, it sells ads. It's in Facebook's best interest to share as little of this information as possible with third parties so they continue buying ads.
2. In the past, Facebook has sold info to advertisers and tracking companies:
https://www.wsj.com/articles/SB10001424052702304772804575558...
That article is a little old, and Facebook may have changed their policy. But the recent story about Cambridge Analytics shows that, at least in some cases, Facebook still shares your information with third parties.
I figure we must promote your calming beliefs. We must allow the the socials' privacy violation pressure cooker to build up its internal pressure to WMD levels. When it finally blows, the socials will be destroyed by the combination of regulatory over-reaction and lawsuits.