For keyboard control, I've gotten into using "Hide <app>" or "Hide others" cmd(-option)-h

This keeps the workspace nice and clean

For switching apps, either cmd-tab or cmd-` or with Alfred App

Indeed, for moving windows to left/right/etc, you may need an app like Rectangle

You _could_ add custom shortcuts in Settings - Keyboard for menu items like Zoom or "Move Window to Left Side of Screen" but it's a bit limited.

What is missing? I guess some people like live preview in cmd-tab, but I've been ok without it.