Here is a little expression tidbit from me to help this thread along:

TO RANDOMIZE STUFF: selectedObjectname.tx = rand(-10,10);

"tx", or whatever, is the attribute you can choose to have the expression applied to.

So, for random particle ROTATION:

selectedObjectname.rotX = rand(0,360);
selectedObjectname.roty = rand(0,360);
selectedObjectname.rotz = rand(0,360);

Try this as a CREATION expression, AND then try it as a RUNTIME expression to see the difference between these calculation types