There is a pretty in-depth binding system that allows for the exact behaviour you are describing. This library is generally a framework with a loose implementation in the name of WindowManager. Most of these behaviours can and should be implemented in applications using this framework.

About "wasting pixels"... What if I (and many others) like the aesthetic and simplicity? There is a sort of magic in never having to leave your terminal emulator. Most frameworks are still keyboard-centered, as many of them don't even have mouse support to replace it with.

Edit: Thank you for your interest though! If you have a syntactically neat way to do the things you talked about feel free to raise an issue and I'll get to it as it comes up.