I have picked up a lot from other zone players, and my clan mates.  I hope it is useful to you.

Not a cheat of sorts, but useful in Multiplayer games,

Model Reborn/boss
Model Reborn/fencer
Model Reborn/acrobat

These give you 3 extra reborn skins.

/cg_lagometer 1

If this works (it does on the odd occasion!) it gives you a "lag meter", the blue line is the server level, and the yellow is your connection level.  When you lag, (slow the server down, commonly known as lagging), your producing the yellow above the blue line.

You can also use the model command to change your character without having to go through the player menu screen.

"\bind [key] messagemode3"  (without quote marks), allows you to type a message to the person directly in your target (default for this is the 'u' key, but I somehow managed to bind that to something else...)