I say get rid of both weapon master and the wpf system altogether, and just replace all of the wpf entries with skills for each weapon type. Your "skill" in a given weapon cannot exceed agility/3. "Weapon skill" affects damage and speed the same way that wpf does now, but does not have diminishing returns like wpf.
This makes agility suck less, gets rid of the "free" wpf for leveling, makes it easier to spend leftover points, allows people to hybrid without requiring lots of agility, creates more diversity...