[2021] so it...looks like a good game...but

Are you able to share a screenshot of what you're seeing? I'm curious what the maxed out UI looks like on your machine because on my highest resolution display, it's massive and can't really be scaled up any more.
The world scale and UI scale have separate settings. Have you also changed the world scale to be zoomed in? There are two zoom buttons on the bottom bar for zooming in and out.

Oh, I'm glad to hear it! :)

All platforms you build (including roofs and floors) are placed on the bottom of the current z level your camera is on. A platform is the bottom face of the block. So, if you want to build a roof on your home, go one z level up, above the wall blocks you have, and place your roof platform across it.

As for resolution, I know the art style isn't for everyone and one day I'd like to make a higher res version once the 1.0 version is out. It's just not something I can do for a while.

You're not alone and the good news is this next update has a bunch of tooltip improvements. :)