I like Bronzong. It's a pretty diverse Pokemon. I went with a flinching strategy on mine.
Let's face it, Heatproof kinda sucks. With Levitate, you have only one weakness. With Heatproof, you still have two. One's weakened, yes, but it's still there.
Increases the chance of flinching, which is vital to this guy's strategy
Iron Head + Zen Headbutt:Both strong, Physical, STAB moves that cause flinching. Not much else to say.
Rock Slide:Strong against Fire-types, your only weakness, accurate, hits multiple targets, causes flinching.
Trick Room:The only way this strategy works is if Bronzong moves first. Given how slow he is related to other 'Mons, this shouldn't be a problem.
I'd recommend starting with an actual attack, just to gauge your opponent's speed. If you're slower, use Trick Room. If you're faster, then just keep attacking. Bronzong's defenses should allow it to take a hit or two.