I actually don't think any of this is true. She is much nicer to her fans than any other celeb, for a start. She has invited hundreds of them to her house to hear her albums prior to release. She's obviously nuts, but that's a different matter.
I think the squad thing escalated in that if any female celeb was pictured with her they were deemed to be in her squad. It was the papers/media more than anything. She was at the peak of headlines being chased about her. She had several v famous friends, most of whom (Gigi, Selena, Blake Lively) still are her friends (Karlie Kloss being the main exception where there's an obvious rift). She has spoken about how she wasn't popular at school and how she took the whole squad thing as like a do-over, and it backfired massively.
The mistake she made was the Katy Perry/bad blood video thing where it looked like she had ganged up on her. Katy HAD screwed her over though, so it's not like she was completely innocent. Definitely, it wasn't nice though. They have ended their feud though, which is good. And she has definitely become more of a feminist in recent years.