dusting off the old TWM configuration

I need a window manager that allows me to
[ ] execute a command by pressing a key
[ ] maximize windows on the left/right half or fullscreen
[ ] switch windows focus and raise/lower windows with keybindings
[ ] keep windows always in the foreground/background
[ ] be easy to configure
[ ] pleasant to work with, e.g. goog performance, little resource consumption
[ ] nice to look at or support "themes"

from my experience most window managers tick the boxes on this list, but TWM
is already installed most of the time