I think it had lots of elements of steampunk and don't think your post is silly at all.
On Whedon being more interested in characters than sci-fi, as a sci-fi fan I have two words: THANK YOU!
Science fiction is less about shooting stuff with lasers in the future and more about the circumstances of the world and the characters. We know through Serenity
is about a bunch of humans who went berzerk and how an "empire" overtook the galaxy removing the rights and liberty of men. That's pretty futuristic! In fact, it's the basis of Star Wars.
And the characters were awesome, particularly Jayne who cracks me up. I think caring about the characters is the most important thing a writer can do.