I said 2 & 3.
Some attempt at ecology is good, but I don't actually want to think about it hard enough to make it really work. Just get me to suspension of disbelief level. If you have a rat bastard at the table picking things apart, then call him a rat bastard, tell him to go play GURPS or Phoenix Command and move on.
I'd default to how I interpret #3: baseline of medieval Europe tech and such, with cultures thrown in a blender. Layer on magic and supernatural bits with just enough attention to #4 (see above).
#2 is where I start to split hairs. I love Eberron, dislike steam-punk (really, any punk in my fantasy), and hate Wuxia. Heck, Forgotten Realms is pretty much too gonzo for me. I'm starting to warm to some weirdness I wouldn't used to have accepted, but mostly in the sense that I'd play/run in a setting that explored specific additions (guns, say), not that I want to expand my baseline definition of what D&D is.
#1 is right out. I want to have fun, but I've never cared for silly.
Now, my big caveat to all the above is that my latest home brew campaign is a setting where large "islands" float in the air. Not sky, because there is no planet. People live on the islands and they can be quite large -- the focus, right now, is one with a lot of Chinese flavor and is big enough to stretch from steppes to an actually sea with mountains and forest in between. Water flows off the edge but is renewed by springs that are, effectively, tiny portals to the plane of water. Heaven is seriously above (as far as folks believe) and hell is literally below -- the worst criminals are sentenced to be cast into the abyss and dwarves are super careful with their mines. Airships are a thing.