no you can not become a gym leader in any game.
You CAN NOT become a Gym Leader in Pokemon HeartGold and SoulSilver or ANY MAIN SERIES POKEMON GAME.
No. So far this feature is in no game.
I don't think so.
In Pokémon HeartGold, you can find the 3rd Gym Leader in Goldenrod City.
Gym Leader Blue
The 14 gym leader in heart gold is in Saffron City.
the 16 leader is in virdinian city after beating every other gym leader
The gym is in Blackthorn City.The gym leader is Clair.
try beating the gym leader
Go to Blackthorn city. The gym is there
on cinnabar island
Violet city