UnrealScript... man! What a mess. But it looks like I have found how to create new console commands (and thus new key binds) for a game type. In Engine.PlayerPawn.uc, starting at line 1138, there are series of "exec function" statements that correlate with console commands. The comment there reads "Normal gameplay execs / Type the name of the exec function at the console to execute it". I'm assuming I can simply subclass any PlayerPawn child class (like TMale1) and put a few "exec function XYZ()" blocks in to define new commands.

Of course the obvious flaw in the class hierarchy model is that if I want to make a change to PlayerPawn, I can extend it, but what about all the classes that already use PlayerPawn as their base class? They don't inherit the changes, so I have to extend each "child" class independently? Yuck! I'll ask around about this one, because it seems like too much of a weakness to be true. (But you never know.)