Hmm.. I used ObjectDock Plus for about three or four years but I never tried to operate the docks with keyboard hotkeys or anything similar. I always figured that if I would have to use my mouse to click on an icon on the dock anyway I might as well just have the dock slide open from its "drawer" hidden mode as my cursor approached it.
But I do see why you would want free-floating docks like that that you could hide away quickly for a full screen game. I once created four or five rectangles of various sizes and placed icons for different categories in each: one for all my A/V apps, one for the two dozen different photo editing & scrapbooking apps, etc. But as you probably know, when any full screen application - game or otherwise - is open over these the shadow of the docks bleeds wight through deeply - I imagine it is Java-related; either way, I had to lose all of those and stick with the hidden tabbed docks. Even those are tough because in the full screen programs if you get close enough to the edges the docks come sliding out anyway!
All that I can think of for your problem is some sort of Autohotkey script that toggles keyboard shortcuts or uses command line controls to operate the docks. Of course I am illiterate when it comes to creating AHK scripts, but if you ask in the coding/program request forum I'll bet someone could create one for you. As for determining if either keyboard shortcuts or the command line to opeate the docks, I would head on over to the Stardock forums - ask Brad if OD+ can be used that way.