Haven't been following the thread much, I'll just answer the original question and possibly play catch-up later.
I don't really have hard limits on what I'll write. I'm not afraid to go dark, although I tend not to. I'll entertain any idea as long as the idea entertains me, you could say. I have few scruples if any when it comes to storytelling. Still, I tend towards pretty lighthearted stuff overall, but if I ever feel the need to go loud I fucking will, with bells on.
There are genres and topics I'll stay away from simply because they don't interest me enough. For example, Romance. I haven't read a bit in the genre and don't know it at all, but a good friend whose judgment I trust in these matters has told me that big-letter Romance, the genre, is especially beholden to formuale and conventions. Haven't fact-checked this, but I've no reason not to take their word for it.
It's not that I'm not a romantic at heart, I very much am, but this notion of conforming to genre staples is a big fuck off for me. I will not write to a recipe, simple as. What I do instead is inject an unholy load of romance—notice the lower case—into my stories, doing my own spin on love and relationships and sex within the larger context of stories that are ostensibly Fantasy or Sci-Fi. I'm a massive sucker for a love story done right, but I'ma do it my way, and someone is going to be wearing a wizard hat for the duration.
Building off of that, I don't really do sex scenes. This isn't because I'm squeamish or a prude or because I don't think I could pull it off, I absolutely could—I know 47 words for the human nipple just off the top of my head. I don't write them because, well, what's the point? To my mind, sex is one of those things that are better on television, and I've got more important stuff to spend my word allowance on. It's possible I'm just ignorant here, as I've seldom read a sex scene that doesn't make me want to leap out of my own skin, but really I don't see the appeal. I mean, I grew up reading erotic totally real tales from reality that totally happened, bro so I guess I can sense some appeal there, but really. I've seen too many poor examples of the sex scene to ever take them seriously. Big shoutout to my boy Joe Abercrombie, who doesn't know he's my boy, but his are the only sex scenes I'll pay proper attention to. The way he weaves humor, plot, characterization, and just the sheer clumsy hilarity of human copulation into his sex scenes is fucking art, and if I thought I could pull off anything remotely like that, then yeah, I would write sex scenes. But I can't, so I don't.
In my own work I thrive on innuendo and flirtation, but if sex ever happens I'll cut to black. My interest is solely in the build-up and circumstances leading to the act. No shade whatsoever on anyone who enjoys that aspect of smut, I'm quite the smutty character myself, but so far sex scenes aren't something I've felt it necessary or compelling to write.
I was talking about Romance earlier, I think. Yeah, I don't touch the genre, but increasingly my work deals with romance in various forms. I love writing about romantic relationships in any degree. I love writing about bitter exes trying to reconcile their differences, and I love writing about hapless twats who're just figuring out they have feelings. It's a realm I love to explore.
And aside from the occasional short story I don't really write stuff set in contemporary times. I don't write Mystery, either, or a number of other genres. Mostly stay under my Speculative Fiction umbrella, but I'll borrow from any other genre as I see fit.
I can't speak for anyone else, but personally, I've had enough of such things.
