You say chick/dik isn’t about good evil but then a couple of words later you reduce them to simple synonyms of those words. Smoking a joint is asshole, turning down a teacher isn’t compassion.
'Asshole' is not a synonym of 'evil'. There's a huge difference between someone who does terrible and despicable things without any moral conscience, and someone who just acts like a bit of an arrogant prick. The MC on the DIK path would be the latter.
The different paths are something of a reflection of attitude but there are admittedly some grey areas there, such as smoking pot which this game considers a bad action when it really isn't, and rejecting Jade and Cathy which is seen as good likely due to the ethical issue of having an affair with a teacher, but neither should really be treated as purely bad or purely good.
Generally speaking, the DIK attitude would seem to be one where the MC is cocky, juvenile,and selfish, whilst the CHICK attitude would seem to be one where the MC is humble, mature, and selfless. Again, there are some grey areas here with regards to some of these personality traits given what we've seen of how the MC handles certain situtations, but overall when it comes to the choices, actions, and lines of dialogue specifically associated with these affinities, this is how these different sides to the MC generally come across.
So if Quinn, after potentially coming to grips with the harsh reality of her situation, were to present herself to the MC as genuinely sincere in her desire to "get out" of her situation, and shows some of that vulnerable, "scared shitless" side we've had glimpses of, as well as perhaps expressing some level of acknowledgement that what she did was wrong, I would think that the decision to help her get out of it is more likely to fall on the CHICK side and the DIK decision would be to tell her to sort her own mess out. Alternatively, a CHICK decision could be a sincere offer of help with no strings attached, whilst a DIK decision could be one where the MC will use/blackmail Quinn into doing something for them later.
Either way, in the event that Quinn could come to the MC for help and the player is presented with a choice, the CHICK decision is not likely to be one that rejects helping her because to not help someone in need would go against the general attitude of that affinity.
One problem with the Sage route is some of her reactions to MC only make sense if you're playing a DIK character with her, rather than a Neutral or CHICK path.
If you reject her advances during the first guitar lesson, it doesn't make much sense that Sage would want to invite MC over "for some fun" at 10PM when MC drunk texts her at Bella's.
And if you're a CHICK towards Sage, it doesn't make sense that she would tell MC he has a big ego as they fuck on Tybalt's bed.
It's also an issue with Bella, as MC constantly joking with Bella and being obnoxious towards her in episode 5 doesn't make much sense if you're a CHICK.
Not necessarily true. The examples provided work perfectly fine on both paths because Sage texting the MC is more about her and her horniness than it is about the MC having a DIK attitude; Sage telling him he has a big ego is because he's not only fucking the President of the HOTs whose boyfriend was the President of the Alphas, but he's also doing it on the bed of the Prep's President and all of that would certainly boost anyone's ego; and with Bella, what could be seen as 'obnoxious' on a DIK path could be seen as him attempting to be 'light-hearted' on the Neutral/CHICK path to try and endear himself more to Bella and get her to crack a smile.