Part of the peril with wanting to kill off swathes of characters and wanting to make most of the cast available for romance is that … well, you’re going to be killing off ROs, which tend to carry more weight than other characters. Which, it’s not like that can’t make sense for a story, but making it unpreventable is probably gonna make people unhappy. You’ll be basically favoring some options over others, which feels like a bad way to go about it, and tbh my concerns about the tone not supporting rampant death haven’t really been lifted yet. I mean, if who dies is decided at the beginning and can’t be changed through decisions, then whether your playthrough is bloodsoaked or tinged at the edges with violence is going to end up being practically luck of the draw. On my playthroughs I’ve barely interacted with Keano, and the only time I encountered Mabelin was during the fight with Killian. If they both die, I’m not necessarily inclined to consider that all that much of a loss. How effective any one death is is going to be very dependent on playstyle (leaving aside the differences in the way characters connect with players, which I realize is a thing but isn’t anything an author has control over so is irrelevant here) and to some extent character build, which again might make it look like you’re punishing players for taking certain steps in the game. If Path A leaves your RO with you throughout and only a couple side characters lost, but Path B kills everybody you care about, why would anyone want to play Path B?
I get what you’re saying with deaths for plot relevance, or to send a message, or any other legitimate reason to kill off a character, but I have to admit I’m kind of balking at the assertion that a preventable death is meaningless to the story. I can think of character deaths in CoG/HGs that I had and then later prevented, and the swathes of relief that I managed to avoid it this time. Or that I didn’t even see, but later read could happen and how suddenly, retroactively nervous I was for that section of the game. Even the potential for death can be powerful–and if there’s a lot of potential for death, it really wouldn’t be hard to make the player unable to save everyone. It doesn’t have to be so direct as “pick character C or character D,” but the actions that end up saving character E could mean that you can’t do what you need to do to save character F, things like that. I get why it’d be frustrating to write a war story where every death can be avoided, but it feels to me like you’re going too hard in the opposite direction.
I have to really echo @Eiwynn’s sentiment above, that extensive character death makes it harder to get emotionally invested in the story, but I want to add that extensive death you can’t prevent feels very different in interactive fiction as opposed to traditional writing. You say a dozen or more deaths that the player can’t effect, and I look at that list and see that that’s half or more of the full cast, that it encompasses almost all of the characters introduced in the first game. In something that has “interactive” in the name, in a game you’re writing for replayability, for the player to feel like each playthrough can be as different from the last as they like–it’s pretty disheartening to read that there’s nothing I could do to save a potentially doomed RO or best friend or family member, especially when theirs would be only one in the long list of dead. I play these games to feel like my character is making an impact on the world, in the story, at least in their own lives, but if so much of the story, and such a big element, is going to be completely out of my reach … maybe the point is that the MC and reader should both feel hopeless, frustrated, helpless, but the beginning of the work really doesn’t paint that kind of a picture and that’s the type of genre shift that might turn people away. I know it certainly makes me a lot less interested in the full story–but, maybe I’m not the target audience, and maybe this is all stuff you’ve thought about.
And, under the cut for only being peripherally related, I have some considerations on the tone of the threatening dialogue options
A while back, I think even on the original thread, someone commented that when reading through the game they felt like the threatening dialogue options (against Killian and crew) felt childish, and I’ve been thinking about it and it seems like the issue might be that they’re a bit too graphic, or elaborate? Like, just taking the very first as an example–it starts strong, with just “I will literally kill you,” a very basic murder threat, said like you mean it, but the way the MC describes killing Killian is just sort of … inefficient? “I’ll strangle you with your friend’s guts” is a threatening sentiment, yeah, and I certainly wouldn’t want to hear it yelled at me, but when the goal of the MC is to sound like they’re about to take direct action … it’s a little weak. There’s probably some obscure story somewhere about a guy who did that to somebody but it’s not really immediately threatening in the way that the MC sounded before. “I will literally kill you” into an over elaborate, time consuming murder plot that would probably be preventable by the larger kids, it falls a little flat. Something more straightforward, “The next time I see you I’ll stab you in the neck,” “I’ll come up behind you and stick a garden hoe in your neck,” basic use of makeshift weaponry (or even using your magic once you know what it is) comes off as a lot more legitimate sounding and a lot more actionable, if that makes sense. I know once I had destruction magic I really wanted to make a show of power, slash him across the face or show him my claws