What levelling order do you use most for Rumble? I'm going pretty heavy E since it seems to be the skill I use most often.

And what do you make of playstyle? Harass with E as often as possible since you're manaless? Or go all in and count on the superb sustained damage of Q for maximum pwnage? Countering him, what do you do - wear him down while dodging his skillshots, hang back and farm passively, or try to force a fight while his abilities are on cooldown?