If I were the OP I'd just quit. It doesn't sound like a productive or supportive place to work, so why bother. There are a million other places to work in this world. And as far as boundaries, it may be worth having a discussion with your HR team if you think anyone has crossed a line. Bosses can't just legally do whatever they want.
Also, regarding boundaries, I set them with all work colleagues starting day one at any job. I have been in management at some level for almost 25 years now and I'm currently working at a Director level position. I love my teams, I support my teams, and I am always looking out for their best interest. We have a good time at work, as we should. But with that being said, I don't hang out with anyone I work with on any level outside of work, I don't accept social media friend requests from co-workers, I don't accept requests to attend parties or activities of any kind outside of the office, etc.. I have zero desire to be close friends with anyone I work with as work to me is nothing more than a means to an end. I have friends, I have family, I don't feel the need to add co-workers to those groups. This has definitely pissed some people off in the past, but they always seem to move on or get over it.
Just my $0.02.
