much of what you're suggesting can be done with a tiling WM. In Xmonad, I do something similar with a concept they label "workspaces", in that a given workspa

much of what you're suggesting can be done with a tiling WM. In Xmonad, I do something similar with a concept they label "workspaces", in that a given workspace has an accreting collection of features which can be summoned and set aside as a unit. The intermediate unit is a tile, and tiles can be hierarchically composed.