base 84 attack and a base 78 defense aren't really conducive to a physical attacker, a defender, or any combination thereof really. Dragon Dance is nice boosting move and if your heart is set on physical, an Adamant DD Charizard would serve you better than your Impish one. Like you said, a 4x weakness to stealth rock means it will loss 1/2 its hp as soon as its sent in, at which point DD is useless and no matter your nature, IVs, and EVs, Charizrd wont survive the next hit. I recommend a Timid/Modest nature Charizard. Base 100 speed isnt too shabby in OU, and is even better in lower levels so you can run modest if you want extra power. HP Grass/Ice will cover most weaknesses Charizard has and coming off a base 109 S.Atk, most pokemon wont survive. I recommend Grass over Ice as water/ground pokemon wont see it coming (or if they do they will run) I would run Flamethrower/Heat Wave (or Fire Blast if you prefer power over accuracy), Air Slash, Hidden Power Grass (Ice if you feel so inclined) and then Roost/Dragon Pulse/Solarbeam (Roost if you have access to it and to help lessen SR damage, Dragon Pulse for its power, accessibly via breeding, and because Charizard doesn't have to many special moves that i can think of other than fire type moves, and Solarbeam if your on a Sun team, also note, if your on a sun team with Solarbeam, HP grass isnt really needed.)
im no expert, but thats what i would run if i went with a Charizard
