we still don't know what Sage is going to ask her father for, I don't think simply to give money to Maya
you keep on repeating the faults that you think the three girls have (I don't understand Sage's... what blackmail? the guitar? she gives it back to him even without knowing with whom Chad cheated on her) but it's clear that it's not like that for MC, so it's not a burden for him
apart from the "annoyance" of having to hear their complaints about how unfair life is, what has it cost MC to still be friends with Maya and Josy? nothing in my opinion
Well, if an MC friend had given his inheritance money to Maya it would have been a stretch (even giving it to Maya being in a relationship with her is basically nonsense, but love...), but listening to them, letting them vent, giving her some advice doesn't seem like that big of a sacrifice to me
I´m talking about plausibility. The dev can write that the MC has wings and can fly, but that's not plausible. Any boy in real life would be badly hurt if were treated like Maya, Josy and Sage treats the MC at the beginning of the game. And would forget and forgive only if there were feelings involved, but not just because "friendship".
Sage´s blackmail? Well, Sage´s boyfriends and/or her pals have stolen the MC´s guitar, a gift from his beloved father. And Sage says to him "if you want it again, you have to spy my boyfriend, that probably is going to beat you badly if he discovers you. Or, at least, you have to promise that you will do". That´s blackmail, in my books. If the MC doesn´t see it like blackmail it´s because bad writing. There are only two reasons a boy would forgive those things to a girl that he barely knows: love and/or lust. If the MC follows Sage´s path, it´s plausible that he eventually falls in love with Sage, because she shows that actually cares about him. But only if he follows that path.
Maya and Josy's annoyance? Well the MC has to pretend that he´s kind of the boyfriend of Maya in front of her father, and Josy ask for his help with her father too... I don´t know about you, but if a girl that I like and seems to like me, suddenly says to me "I´m actually a lesbian and into a relationship with another girl (that you like too, and seemed to like you), and now, please, let´s be friends and help me with my problems with my family and my girlfriend..." I would say "no, thanks, no. Good luck with your problems, but no". But... yeah, the MC is a saint.
Maya could have her problems solved just being discrete with her father about her relationship. But she´s a drama queen... Well, at least Quinn, Riona, Camila or the best of them, Lily, have the guts to take care of their own problems, even if that means to do really nasty things. And don´t take advantage of the MC´s good faith. As far as we know, those girls don´t have access to daddy´s money, but only if... They just don´t have any daddy´s money. So they have to take care of their own money problems, the best way they know. How do you think Maya would react if she would have to listen old drunk guys say to her "whore, show me your tits" every night at work, like Lily?