I am no big fan of Facebook corporation. Like Google, they are here to exploit our data and I don't love that. However, Facebook's claim to intellectual property that you put on this site is not that weird, extreme or unreasonable.
We all post stuff here so that people can see it. The law says that you own the copyright when you type stuff, post pictures, etc. If Facebook shows that information to your friends, Facebook has violated your copyright and you could sue them.
The reason their terms of service include a license to your posts is so that they are not at legal risk when they show your posts. It's necessary and reasonable.
Some people get upset that the license language allows them to create derivative works. This is also necessary. Eg, any of us can request a copy of our Facebook page/history. This is a derivative work and anything that is in it would be a copyright violation without that provision.
Privacy is a weird issue in the modern age. One big shot I pay attention (Bill Joy) to said, in the nineties, "Get over it. There is no such thing as privacy any more." I think he was probably right.
However, I retain a certain amount by not posting things I feel private about. Facebook will never be able to reveal my important secrets because I don't post them. What I do post, I want known. Honestly, I think that's true of us all.
Which is to say, don't worry about Facebook. Worry about what you say. Facebook is a wonderful thing that provides us with the ability to have conversations with each other though we are separate in time and space. Honestly, I rejoice in it. I think you should, too.