Is there a way to configure mouse preferences to move the pointer automatically to the default button?
I believe that this is window manager-dependent. By default, in Ubuntu you're running either Compiz or Metacity. I don't think that either of those WMs has the option you're looking for. But there are many WMs out there. I seem to recall encountering at least one such WM years ago when I used to experiment with window managers. Of course, I no longer remember which one it was, but I suspect a Synaptic and/or Google search for window managers would yield some interesting reading.