impossible
If you have a ditto then you can put any gender (except a none gendered Pokemon) and get the exact Pokemon you want
You can not combine Pokemon in any game. you can combine digimon and you can breed Pokemon. I hope this has helped
There isn't any
No. There is no way to combine Pokemon.
No, there are no other regions in Pokemon Diamond.
buy a action replay or cheat cartridge with Pokemon diamond on it
male and female of the same Pokemon or ditto with any Pokemon
there is no cheat use a gameshark or buy whatever Pokemon you need on eBay. also, if you are having trouble breeding for the IV, EV or Nature you want it looks like you can purchase any Pokemon you still need.
In Solaceon Town there is a Pokemon Day-Care where you can leave two Pokemon, one male, one female, and make an egg. But you can't leave any two Pokemon in the Day-Care and expect eggs. Google 'Pokemon Breeding' and you'll find the answer.
No
Umm... sorry if this sounds rude, but of course there are Pokemon in Pokemon Diamond! It's one of the Pokemon games!
yes