Did I get all that right?
I understand the confusion. I also came from Darkest Dungeon and was initially wondering about a lot of things. If you don't mind me writing a litany, then I'm happy to help and let me cut in where I think you missed something (or wrote a "??").
Affliction: triggers during combat at maximum lust. The type is random, but weighted based on desires (??)
Correct, but I'd add that all afflictions are technically negative. Desires of a character does affect the randomized affliction a girl gets. The
Desires primarily, which reduces the "good" (Clearheaded) affliction chance the more corrupted a girl is in that desire. So if you want the Clearheaded affliction, which is generally what you should want unless you aim for some suboptimal roleplaying, then you should strive to keep the Desires as low as possible. You can check the current weight spread on the Desires tab on the character screen. Additionally, some Quirks and Hypnoses can also affect this ratio, notably the Clearheaded quirk and the Mantra of Idealism both increasing the chance for the "good" affliction. The reason I'm writing "good" is because Clearheaded still increases the Main Desire so it's still technically bad, just not potentially adventure ending as other afflictions can stunlock a girl for many turns.
It's akin to the Test of Resolve from Darkest Dungeon, but you can only get neutral or bad things.
Desires are a measure of how corrupted a girl is. It's basically an extra stat system that usually means "higher number is bad". On the Desires tab of a character, you can hover your cursor to check what each step does exactly to the girl and unless you want to roleplay a character, you should generally avoid getting these up as they are pretty difficult to decrease.
Desire (or Main Desire, topmost): Increases with various effects, but mostly due to Afflictions and other Desires. The lower the better objectively. Higher numbers reduces your Clearheaded Affliction chance.
Boobs (don't ask why this is a desire): Equivalent to the current breast size of a girl. Higher is not necessarily worse, as different levels yield different results, both benefitial and not outside of
personal aesthetics. Smaller boobs yields significantly less daily milk when working as a Cow at the Farm, but it also has no Clearheaded chance penalties. Larger boobs are the opposite. Additionally, many Quirks and Equipments (gear, clothing, etc.) and Parasites work differently depending on the breast size. For example, the Chestbinder equipment gives you a damage increase for being flat while nipple parasites grow faster in bigger tits. Too many things change the size of breasts to list here, just check a description of any particular thing and it will show it if there's a correlation. Later, you can change the size manually in the
Submission: Primarly, this increases daily if a girl has cursed equipment (marked with a lock on its stats), the more such equipment, the higher the daily increase. Uncursed (broken lock) equipment still increases this desire. Higher levels significantly impacts the Clearheaded Affliction and increases the Main Desire daily. The less the better.
Exhibitionism: Same as Submission but primarily increases by taking
Durability damage, the damage type that removes clothes from characters on a mission. The less the better.
Masochism: Same as the two above but primarily increases by taking any regular damage, either physical or magical. The less the better.
Libido: Same as the three above but primarily increases by taking
Lust damage. The less the better.
So how do you remove them? Very slowly, if at all. For example the Devout quirk reduces all except Boobs by 3 every day if she spends the day in the Church building, which is one of the most predictable option. Since the maximum number is 100 for each, it's better if you try your best to avoid getting these numbers raised. Finish fights fast, use a tank character to attract and soak less damage, avoid leaving your girls with cursed items for too long and so on.
You can give your girls a
Mantra in the Mental Ward building, which are literally just Player-given
Hypnoses. These can be very benefitial, especially for converting bad
Crests but it also comes at a -2 all stat penalty. The
suggestibility of a girl reduces the cost of giving a girl a Mantra.
Hypnosis: forces certain actions based on type. Type depends on ??.
Not necessarily forces actions, some of them also does other things like increasing a
Desire, but it's more or less correct. The type you get seems completely random, atleast I didn't find any patterns so far. You can cure them at the Mental Ward building at an initially steep 50 mana price but most of them will decay over time. Some can be even more benefitial than bad, either the aforementioned Mantras or even some random ones.
Crest: some kind of magic curse?
It's a hentai trope, almost always meaning some form of corruption, intense pleasure or serivute. In game, it is indeed a magical curse. Their growth rate from certain enemy attacks and Mantras depends on the personality traits of a girl, you can check the growth percentage if you hover over a crest progress on the personality tab of a character. I'm not entirely sure if you can remove all of them completely, it's better to give a girl a Mantra hypnosis at a Mental Ward to turn a Crest that's bad for a character into one that benefits their playstyle. The Purity Crest is bland but very effective if you plan to reduce the Lust intake to avoid getting higher Desires. The Vanity Crest is good for frontliners. If you're unsure, and a girl fights on the front two positions, then the Vanity Crest is simply an improvement over even not having a crest at all. The Lust Crest (not to be confused with Lust, the damage type and threshold that leads to Afflictions) is pretty good for high damage dealers, like Mage or Rogue, but will eventually increase the bad
Desires over time as it deals your girl Lust damage every turn. The rest are situational and mostly bad.
So, in general, it looks like the game encourages you to min/max by finding the right crests, hypnoses, and parasites that match a certain class and combat role? For example, a healer role would benefit from crest of servitude and obedience affliction.
The game definitely encourages you to min-max, but it's not strictly necessary. You could use general common sense to avoid things that seems really bad and you'll manage with pretty good success. You could have a few min-max characters, have a lot, or just use roleplay characters, like I tend to get my Rangers with parasites because it's the closest thing to a beast master specialization you'd expect from a Ranger in any other RPG. It's not optimal, but it's not outright horrible either and it gets the job done.
As for min-max, you could get a flat-chested Rogue with flat-chest and high-lust damage boost items, Aggression personality traits, Aggression quirks, Hypnoses that gives you damage and/or free retalliation plus a Crest of Lust and she will melt almost all enemies that she encounters.
You could get a low-lust Crest of Purity Paladin that can also deal high damage with the sword that gives buffs on low-lust, or get a low-lust Crest of Purity Alchemist that can literally one-shot some bosses if built well with the Trickshot ability.
As for healer, yeah Crest of Servitude is generally better, but you could get the Motherly trait which increases healing based on Parasite growth, grab a brain parasite which further increases healing, and then you could go for the Crest of Desire to raise the parasites quickly (and sell them in the process).
It's really up to you. Unless you purposefully build all your characters badly, even passively doing okay things will land you success. Even if you bombard your girls with bad combinations for the hell of it, you can succeed if you know the game well enough.
I like the concept. The Darkest Dungeon-style gameplay is great for a porn game, but I can't understand the hentai logic very well. Would be nice to have a version with a bit more horror and more non-con / reluctance, with a high difficulty level so that I actually try to win but lose often enough to see the sexy content. Best if there would be tactical options to trade some dignity for the sake of survival.
I really love Darkest Dungeon so this game was also a big hit for me. The H here content is okay-ish but I just treat this game as Darkest Dungeon 2 until the studio finally gets their shit together. I think the game is already pretty non-con despite its cartoonish looks, but I agree on the horror aspect.
Hopefully I could clear up all your questions in your post.