Is there any way to get the dock to use "intellihide" (this is a carry over from various docks in the linux world). Basically that means that the dock is always visible if no windows are in its space, but if a window gets too close, the dock reverts to autohide type behavior. I can only find "autohide" and always visible. I would prefer something as I described.
I have developed an application (mainly using AppleScript) that does this, or at least very close to what you want: https://github.com/gjherbiet/DockIntellihide.app
No. I don't believe that this is supported by Apple at this time.
Sorry for the pessimistic answer, but to my knowledge it's true.
There may be ways to run Docky or the like through macports or fink.