Indeed. It should not be a surprise that tiling window managers are probably preferable to every method of input other than mouse. That AU probably would be a good one.
(Keyboard included and especially. Do you know the keyboard shortcuts to move/resize/arrange windows and when was the last time you tried to use them? Part of my love for tiling window managers came from daily use of a laptop with a bad trackpad and wanting to automate more things with the keyboard.)
Hmm? I’ve used my Surface Book in tablet mode from time to time and see no particular problems with it. Every window becomes full-screen, swipes from the screen edges do meaningful things that are similar in effect to what Windows 8/8.1 had. I wouldn’t describe it as in any way nasty by comparison. Do you have something particular in mind? (Or were you perhaps unaware of tablet mode?)
Up until this year, for example, the keyboard used to _overlap_ the main tile -- but only if you have one tile only, hiding whatever textbox you actually wanted to write in if it was in the bottom half. If you had two, then the keyboard worked correctly as in windows8.
This was broken for 5 frigging years. The general consensus was that tablet mode was more problems than it was worth. They fixed in some recent release but is still buggy as hell (windows will not return to full height and instead be partially moved off screen for some reason).