Interesting info here.
I've wanted to do an action bar plugin, sort of like Dominos for WOW. Basically hide all the original UI elements then provide action bars, a bag bar, and another button bar for things like traits, etc. These would all be independent and not have any graphics attached, per se, so that they could be moved around at will and arranged in any manner the user wished. They could also then be resized and action bars could even have the option to "scroll" via hotkeys.
Given the limitations mentioned here though, it seems that such a piece of work is simply not possible yet, especially the lack of keybindings.
As far as skins that hide the action bar graphical elements, what skins do more experienced users recommend?
Also, again as a long time WOW user, I've considered developing something like Titan Panel or Fubar, a small thin bar that can sit along the top or bottom of the screen and act as a display agent for plugins that provide information, such as current gold totals, bag space, reputation gains per session, DPS, etc.
It took the WOW community several years but they ultimately agreed on the Lib Data Broker specification for such plugins, which then allowed for the creation of Lib Data Broker display agents that would provide the displays for those informational agents.