As a city gal, Masculine, for me has some overlap with your definition, but not completely.
I do agree that a generally sturdier build is part of it, and a confidence in what they're wearing. As for it being flashy or not ... I know a lot of Ren Faire workers. Who are perfectly Masculine and look great in a doublet and nice pair of velveteen hose. Because "Masculine" fashion is not a universal to me. It's things that emphasize physical male-ness (features of upper body strength, strong legs) and give the wearer confidence in emphasizing those aspects of their appearance/personality. So yes, we need more cuts of basic jeans, more t-shirts, more button downs (not necessarily plaids, though I have no problem with them) but we also need more kilts (I loved the utilikilt in Dream Home Decorator) and more sharp suits (ZZ Top was not wrong about Sharp Dressed men.) I'd also consider Poet/swordsman shirts to be masculine, though not in a modern sense.
The "body hair" thing is a bit touchy, because certain Ethnotypes *don't have a lot of body hair* and equating body hair to masculinity is undermining the masculinity of those groups. Effectively saying that certain groups *can't* be as masculine because they don't have this particular characteristic. Which is garbage, imo. I'd like Body Hair to be an option, because I've had some sims it would suit, but I don't "need" it for Masculine sims.
As for jobs - I do agree that Construction should be a full time job. And we need cars/things with motors for sims to tinker with (even if we can never drive cars.) While I don't think that either of these things are masculine only, the are masculine coded and should exist for masculine coded sims. Most of my specifically Masculine sims are business men, lawyers/judges, chefs (a very male dominated field), Athletes, Gardeners and Engineers. I did have one who was a romance Novelist, though. (It was a game generated sim who coded very masculine in appearance. He just happened to have the Romantic trait and the Novelist aspiration and so when he joined the family, I ran with it.)
