Use a action replay
it is in between Mahogany town and Ekruteak city
Yes.
You can't. You can get him only through an event.
It's Darkrai. You can't get him in Heart Gold.
Mt. Mortar after winning at Blackthorn Gym. You will need a Pokemon that knows waterfall and an open space in your party because he will give you a Tyrogue after you beat him in a Pokemon battle.
East of Ectearuck city
Pokemon Heart gold is different from Pokemon Gold cuz heart gold has better graphics new Pokemon and new events
Through an action replay code
the third gym's HM is Strength. Receive from the Hiker who comes out of Mt. Mortar on Route 42
Go west of Mahogany town.
you can i dont know the awnser
waterfall, surf