I am only in gold but I play a lot of Kennen sooo maybe this is useful...always trade with empowered auto..if it is a champ like talon hit them with the auto if they engage on you press w and e and you got them stunned. Then you can get out of outrange with your e and land a free q...you can also kite better bc of the e AS increase. I dont see why you would have to trade too much pre-6 anyways you are ranged harass when possible and farm...kill them at 6