I have a few notes on the Game.
For the chaos player- he had a very strong list however
IIRC when his plague rhino's where Immobile He chose to sit in them for a turn then get out and start advancing that's really it .
For the Tau player- First off I agree with hivefleetmonolith in that the stealth suits where a waste of points and should have been replaced with Crisis suits, also It seemed like you did not use your assault bounce move to full effect. I would Have assaulted with the kroot into the plague marines once they reached the cover. I feel target priority with the piranhas and the devilfish wasn't that good I think they should have gone after the oblits,or at least went back to fish of fury to some effect for your firewarriors so they could have shot some more. Other then that I supposed that you had stuff in your list to help you with multiple situations and that's good in general for playing games.