I can't relate to the military thing, as I've never served, but I have had a couple of very close friends who did, so they shared a little of their experiences with me. I definitely wouldn't consider a military story in the same light as a typical fantasy adventure story. I wouldn't expect romance to be prevalent in that circumstance. I think the experience of being a soldier, in a very strict hierarchy with an ironclad chain of command and a compulsory code of conduct, would be quite different from being a member of a standard D&D adventurer party. A soldier probably spends a lot of time doing exactly the thing that they are required to do, in a very focused way, as you've described, whereas a fictional fantasy "hero" mostly does whatever the fuck they want, and doesn't really answer to anyone. I wouldn't expect romance in a cop story, either. I mean, I didn't think that there should be romance in Disco Elysium, as that was about two detectives trying to solve a murder within a very short time frame. If there was an RPG about being in a modern military unit, it wouldn't feel weird to me if romance was never a factor.
That's really interesting about PTSD, I didn't know that. I can see it, though. Trauma is a real tricky thing. I kinda wish it was a topic that more RPGs explored, actually. It would have to be done carefully, of course.
"To be honest, most of my (few, fragmented, and unreliable if) fondest memories of former flames usually concern those things that went wrong which we found joy in anyway, rather than those perfect nights." Oh hell yeah, THIS. I fuckin love disasters, that's where I really bond with people and have the most fun. It sounds crazy to say that disasters are the most fun, but I'm kind of messed up anyway. I get weirdly gleeful when shit starts going horribly wrong. Especially if I'm with someone, and then I can try to lift their spirits about the whole thing. "It's an adventure!"
Well, okay the massive scale of human potential, sure. I mean I guess on a grand enough scale, most anything can be considered insignificant. But I think most humans don't really do much with all that potential. Most of them probably don't contribute much to the world beyond reproducing. Some not even that. I do like the IDEA of that potential, though. I am always wanting humanity to evolve to new and greater heights. It seems slow-going, though.
How characters handle visceral violence is something which I feel is handled exceptionally poorly in almost all games (I actually cannot think of a single game that handles it well, but because I haven't played every game I will use the word almost just in case 1 exists). Games go to a lot of effort to provide a multitude of ways for you to kill, maim or dismember enemies, but next to no emphasis is put onto the emotional toll this would take on the character. In my opinion, this is a sorely missed opportunity. To be fair, I cannot blame games entirely for this, most fantasy novels avoid dealing with this topic as well, it isn't easy to write about and it doesn't make for fun reading either, even if it is deeply thought provoking and emotionally moving.
There is a great book called Crime and Punishment which deals with the mental anguish of the protagonist, following on from him murdering a pawnbroker. It doesn't make for light reading, but the depth of the characterization there really does make the reader stop and think for a bit. I am not sure how a similar effect could be conveyed in a game, maybe with dream sequences over the people you kill, or something like that. Either way, dealing with human suffering in the video game format is hard. I don't think Faerun would even be the right setting to attempt to do something like that, not without having a much more focused campaign. For such a story to be effective, you would probably need to first convince the player to view the NPCs within the world as real people, then make them emotionally attached to those people, then force the player to kill them off.
Even if you could do something like this successfully in a tactful manner however, there is a question of whether you would even want to. Most people play games to blow off steam and relax, not to stop and think about complicated moral dilemmas.