I have no qualms about unfriending people. It's just social media.
I unfriended/blocked my mom, for chrissakes. I also unfriended my ex and his family, and a lot of other people whose contributions to my life were little, or were harmful. I'm Facebook friends with a lot of people I don't care about so much (if we're being honest) but since they don't offend me, so be it.
There are also ways to arrange people into groups so you can restrict what they see of your information. I recommend this for family.
The rules of doing social media well are all about having good personal boundaries. If you don't like it, if it makes you cringe, don't read it. You can not read it by hiding or blocking the people that make you squirm with discomfort and/or rage.