I can't help but notice that you didn't list a whole lot of traits that would be considered vital to having a fairly human sillhouette. There's nothing here about obligate bipedalism, for example, or having just two legs in the lower part of the body at all. There's nothing here about how the forelimbs are articulated, and whether it would look meaningfully like hands or an array of dexterous tendrils or something. And all this gritty realist speculative biology seems out of place when most sci-fi is basically a particular sub-genre of fantasy anyway. Even being generous to the sci-fi writers, supposing the universe works in a fundamentally different way from how ours does (breaking laws of relativity and entropy, commonly), why can't some ecosystems work out to stretch your imagination of what could be an advanced species? It all seems very narrowly prescriptivist, even beyond the fact that this is fiction to the point of taking negative liberties with the bounds of what is truly realistic.

Edit: idk, it just seems obtuse. Like, "Advanced life can only be carbon-based because being that way affords these benefits" without considering that other models could provide other benefits (I'm sure you know better than I about the use of silicon-based life in speculative biology). And that's if the subject is addressed at all.