I think we see things differently here, I don't know if you're right or if I am, but the way I see these scenes is really different from how you see them.
Just a summary here to wrap up my position on my point of view:
When you mentioned that she likes to fuck people, I was thinking about something serious, not teasing.
Something serious would be swapping some girl's pills for sugar, with the intention of making them pregnant, however, as she did that with Dawe I don't care about that, he wouldn't get pregnant taking fake pills, but since Arieth has been taking Dawe's pills, we can say that
Quinn fucked Dawe and Arieth.
And about Josy, she was teasing Tommy, I didn't see that as something serious, and Josy's list was the same as Maya's, if she completed it great, she would be a candidate for the restaurant, or at least a HOT, if she didn't complete it, good too, she wouldn't be a HOT, the joke with Tommy would be over and that's it.
As for her treating the MC badly, Sally treats him much, much worse, Quinn's attitude is to push people away, and we see this when the DIK MC insists on approaching her.
I mentioned the taser as the worst thing she did, but what if Quinn (DPC) didn't see it as something serious, no one got hurt, no one commented on it, not even the MC.
About her doing things behind Sage's back, Sage tells the MC that she likes that Quinn handles things for her, we know she's the VP, and it's almost certain that she'll be president of the HOT's in a matter of months.
And about her treating Rio badly, even DPC calls the girls “Quinn's girls”, I like Rio, but she's not at Quinn's level in the chain of command, she does what Quinn tells her to do, and what did Quinn do wrong with her, hide things from her?
About Quinn wanting Maya at the restaurant at first, that's obvious, Maya is attractive, and she was the one who showed interest in becoming a HOT, Quinn didn't know Maya well enough to know if she would be good for that or not, and when she realized that she wasn't restaurant material, she made it difficult for Maya, Maya didn't get the list the day she knocked on HOT's door, only later, and we know that her list is different from Lily's list.