I experienced some of these issues. For me, what eventually clicked is either simple automated tiling (xmonad with fullscreen and split horizontal/vertical) or Emacs-like manual tiling (StumpWM). I don't have a huge screen, so more than two windows is a stretch. Both of these WMs are decent at floating layouts.
Besides, I find the simple tiling offered by the stock GNOME Display Manager, which is similar to the way I use xmonad, good enough. Given that GNOME has great support for floating windows, that is perhaps an option you should look into.
Besides, I find the simple tiling offered by the stock GNOME Display Manager, which is similar to the way I use xmonad, good enough. Given that GNOME has great support for floating windows, that is perhaps an option you should look into.