Okay, I think I got it compiled. Really excited. As a matter of fact, xserver-xorg-dev was the first thing I installed - but I never did remove the 11-x11-synaptics.fdi file, though I had removed the synaptics driver through Synaptics (whoa... ).

As far as your questions:
  1. This is a standard two-finger click, although it'll vary depending on how close they are.
  2. Nothing. This is actually very pleasing about OS X, and a tiny bit jarring when using Linux. Leave your palm (or another finger) on the corner of the touchpad and it has zero effect.
  3. A single-finger click. I actually do this a ton.
  4. A two-finger click.