3) now that I know youre into it, checks out, I can see how it might have influenced your writing now. They don't sound like Sugimoto and Asirpa at all, but the way they relate and talk to each other has that same vibe, it's a relationship you do want to see more, in a variety of situations to see how they clash or meld into each other.
I'm also writing one that doesnt follow convention, and doing the exact opposite of the very advice I'm giving, but it's what fit for me, so in the end we can only create whats natural to us.
5) I think that works well too. It's two extremes, one right choice and 4 that lead to a dead end makes it predictable, as does no single choice ever leading to a death. So the only way to really make it feel real, is sometimes it being deadly, and you not being able to tell you doomed the timeline because things seemed like a messy success as usual. Balanced stakes keep them vivid in the player's mind (and VNs have the advantage of lightweight navigation, so such dead ends dont hurt in a playtime measure as much as it would in different genres.)