That's a pretty weird definition of mostly usable.

Just to recap: you have no reliable WiFi or Bluetooth, no external video output, duff power management so your laptop can't be treated like a laptop, and you can't type in your native language easily. Sounds great!

The menu is at the top of the screen because you can move there more quickly with a mouse because you can hit the edge of screen therefore don't need to take as much care.

Click to focus is a no-brainer, no accidental focus changing and clicking doesn't take appreciably more time than just moving, compared to the recovery time from occasional misfocusing.

I have some sympathy for desiring to be able to focus windows without raising them. It'd be nice if this was a right-click-on-title-bar feature or something. Obviously it shouldn't be the default, because you are more likely to want the window raised than not, so the common case should be the quickest and not take two operations (focus and raise).

My comment was mostly intended to be humorous. However, if you define sound as kinetic vibration, then there most certainly is sound in space. Everything out there can have internal vibrations. There is sound within the space station. The difference is that those acoustic vibrations just doesn't "move" from one thing to another through space. They are trapped within whatever generated them.