Disclaimer: This answer refers CCSM (
compiz-config-settings-manager) which should be used with care. There is a probability of locking yourself out of Unity if handled improperly.
Super + W spreads all windows in the current workspace. I assume that is what you are referring to.
It is possible to bind these events to keyboard shortcuts or mouse clicks (with or without modifiers) Left click selects a window and can not be changed as far as I know.
- Zoom into a window, but do not select it
- Close a window
- Pull window
These features are handled by Scale Addons plugin in CCSM. The plugin does have an option to bind a shortcut to
pull Window. Probably that does what you want. Screenshots are provided below for reference.
The problem is, I haven't yet figured how to spread all windows from all workspaces. No combination worked, yet. You can try various combinations in Scale plugin to see if you can achieve this. Once you spread all windows from all workspaces, the shortcut assigned to
Pull window should do the trick.