re:Non-Programmer's Guide to Current Croquet Functionality

Unfortunately for what you are trying to accomplish, Croquet is like the Smalltalk in which it is written in that it is such a wonderfully integrated interactive dynamic environment that most of the documentation is actually self described by the code.  Okay, that's just a geeky way of saying there isn't much documentation outside of the code itself.  At least not that I've found ...