I think CQ route is still believable for now if you go with the theory that Evelyn is getting spiked with elysium.
-CQ Lexi: Already made my argument above that she is pretty slutty either way, but she gets way more hammered in the CQ route so could explain her behavior
-CQ Zoey: She flashed you during the pizza delivery, if you don't give Fiona a handy yourself she will suck her off in front of you during the sleepover, then she has sex with Ashe and lets her know she isn't looking for a serious relationship. Those are all canon events from before the route split. Really not out of character she would have a fling with a literal pornstar if she ran into one during her vacations (Jordan is one of the porn actresses in that gangbang porn video Ashe can watch early in the game)
-CQ Evelyn: This is the one who behaves the most out of character in the story...until you consider the possibility that she is being spiked with elysium. Outside of the CQ route, the game makes a point to mention that Stella took her out for dinner to eat oysters (game explicitely points out they are an aphrodisiac), but that ultimately she didn't really feel things click enough and she decided to stop things at the dinner itself.
Now consider the idea that in the CQ route, instead of using something basic like oysters to get Evelyn in the mood that Stella would instead use Elysium, a strong aphrodisiac drug the game soon reveals that it easily dissolves in water and is tasteless. Then take that thought and consider how much emphasis Stella's introduction places on the glass of water she was holding in the kitchen when Ashe runs into her, and how the water in the glass was faintly bubbly when she sets it down on the counter.
I fully believe that might have been a hint that Stella was taking elysium to make the sex even better for herself too, which also helps explain her extremely degenerate behavior in letting Ashe watch and masturbate herself while watching them. If she had elysium for herself, not hard to assume she could have spiked Evelyn.
-CQ Rachel: I don't know, Rachel is mysterious. Some people are convinced she is already up to no good regardless of the CQ route so hard to gauge her character. Even if she is a good person with no dark secrets being kept from Ashe, I could see the CQ route for her playing out like she gets super pissed about Ashe being so overprotective despite the fact they agreed that Rachel would never romantically belong Ashe so she plays into Natasha's mindgames just to spite Ashe.
I generally agree with all of this, just with a few caveats for Evelyn and Rachel.
We don't know Evelyn that well, Ashe doesn't exactly come off as someone who has deep conversations with her mom, and Evelyn doesn't come off as someone who talks about her sexlife openly, so she could very well be more on the promiscuous side but that Ashe hasn't ever noticed it before.
It's information that we aren't privy to, so while getting drugged is honestly the more logical explanation since NTR routes thoroughly
loves corruption and having a mother-figure get drugged/manipulated over time to become a wanton slut is entirely within that alley, there could also be the explanation that it's simply the way she's been yet she hasn't really had the desire or time to act on it due to the loss of her partner.
And Rachel, honestly, it's hard for me to see her as someone who doesn't act after a selfish agenda, so I can definitely see her going way too far just to spite Ashe because 'it's her life and she gets to choose, not Ashe' type of deal, I can equally see that girl doing this because she enjoys using her sister as a twisted sexual outlet as she knows Ashe can never have her, so she enjoys tormenting her that way.
Other than that however, I fully agree with the assessment of the other characters, especially that Lexi seems to naturally be more slutty than what most seem to assume.
EDIT- honestly I wouldn't be surprised if it turns out that Rachel talked Evelyn into dating again, given Rachel's.. peculiar sexual interest which seems to be centered around Ashe, she might have thought that she could have a double whammy there. Though it's unlikely as she clearly has no idea whether or not Ashe has any interest in Evelyn to begin with, but it popped up into my head once I started thinking about how Rachel is currently acting and what she's like.