Given the power of Paul Mykock's conglomerate, I'd say we're talking about a system where corporate interests dictate government actions. Traditional fascism has usually had government and industry in bed with each other, but many modern dystopian science fiction tends to place greater power on the corporations than they had in the 20th century.
I guess, big parts of politics is at least not interested to, what happens in the schools to the students, as long, as there is no public outcry and they reach the promised results (and as long as they don’t see it directly). Interestingly just the first scene indicates in this direction, where the secretary of education is upset about the presentation and the headmaster tells her, he always reported about what he did, the secretary just answers: „Well, I clearly didn’t read your fucking reports, did I?“. Also that the headmaster isn’t put in jail, for what he did, because the secretary fears about the negative publicity points in this direction.
The way you describe it reminds me of the 1967 movie In Like Flint. In the first movie (Our Man Flint), he was taken care of by five beautiful women. In the sequel, there were five different women in his residence. When asked about it, Derek Flint explained that the five of them from the first movie had gone on to be successfully married. It makes it sound like Derek Flint surrounded himself with five women at a time in a bit of a M/s apprenticeship that helped them to find their confidence and power through submission. This seems to be what you're suggesting here. He's training these young women to find their strengths and achieve their potentials.
Well, I guess, I’m a little too good with the headmaster. He is still a pervert asshole, who has beneath the education goal of course also the goal to satisfy his own sexual interests (which weighs often higher than the other one, why he has to bow his own logic). And his deeds would be in the normal world not at all to justify. But he is presented in a world full of corrupted assholes. And his lewd deeds are mostly either represented as within the rules of the lewd world and/or not that bad for the students, which seem in the end often to keep some gains or joy from it. Thus in the end, the students will have found their strengths and achieved their potentials (as you say). This and that he will surely finally start the fight against Mycock (for whatever reasons) makes him an antihero. But I think, there are some exceptions (like the first scene with Sarah), which I personally don't like.
I find it interesting in this regard, that at least in the second chapter, Altos sometimes lets the students make the lewd suggestions. So in the football match, the students indicate, the looser could play bottomless, the headmaster just has to agree and make it a rule. Same is in the scene of the Headmaster, Debbie and Rachel where the headmaster tells Debbie to decide, where the Headmaster should cum and she says, he could cum in her mouth, totally different from what she wanted herself from the headmaster. That makes his deeds actually seem a little less bad, as even the students are behaving lewd to each other.
Mykock and Co. probably want these young women groomed to server the corporate bosses, but I expect the Headmaster has a much more lofty goal.
Yes, I guess also, that Mr. Mycock is planning to make a slave trade with the students, what the Headmaster is heavily against because of his own goals (not because he might be negative about slave trade, I rather guess, he wouldn't care about). But I guess, the harem ending won’t be at least for every girl. I personally think, you can determine through your own decisions (primarily in possible future updates), which way the girls will go after graduation. By now, I see e.g. Lucy head this way, where you can choose between 4 paths (dom-rom, sub-rom, dom-care and sub-care). Those paths are almost the same regarding the actions they cause, but quite different regarding the relation between Headmaster and Lucy. So they potentially could lead finally to four totally different endings with one being Lucy in your harem (in a romantic relationship) and another maybe Lucy getting a self-confident Leader of an Escort Service (in a caring relationship) after her graduation. Maybe Priti is another one (What will happen, if you give her pictures to Wilson and never revoke your decision). But I could think, this might lead even to a totally bad ending. But that’s totally unclear, as her path is yet to be fleshed out in the next update.