As far as I know, you can get a Lava Cookie from the lady who is looking for her Suite Key, near the east of Pastoria City.
There isn't any
No, there are no other regions in Pokemon Diamond.
buy a action replay or cheat cartridge with Pokemon diamond on it
No
Umm... sorry if this sounds rude, but of course there are Pokemon in Pokemon Diamond! It's one of the Pokemon games!
There is no Lumineon in diamond
Any Pokemon (includingWailord and Azelf).
I don't think there is!
You can buy Pokemon Diamond at EB games and Game. Any game shop.
Yes.
No there isn't!
there aren't any.