Yes it will work as the DS is not region locked.
The game will work yes. But if this game has wireless play then i don't know if that will work yet. It probably will, though.
Yes, a Japanese version of Pokémon HeartGold will work on a DS from Australia. The Nintendo DS can play all games regardless of what country they originate from.
American DS games will work on an European DS. The original Nintendo DS handheld game console was available between 2004 and 2007.
DS games are region-free, a Japanese DS game will work fine on a DS from the US.
It will work on an American DS. My DS is American, and I just bought a regular DS charger off Amazon :)
yes
The controller will work and not the games
Yes, the DS is not region locked.
Yes, they will work since DS games are not region locked.
Yes
no american games don't work in australia
Yes it will because DS games are not region locked