[aldanor]

The solution (although somewhat rough around the edges, but much, much better than other options) is to use a tiling window manager like Yabai. It will completely change the way you work with windows and spaces in macOS. This definitely solves your (1), especially with the help of `skhd` to map your keyboard shortcuts. Another option is Amethyst but it's a bit less configurable (although it supports stack layout for windows).

(3) can also be solved. Go to system preferences -> accessibility, check the "Reduce motion" checkbox. Now the spaces can be switched almost instantly without the annoying animation by using keyboard shortcuts.