no but you must have the national dex on platinum
no.
Darkrai is unobtainable in the original Hoenn games and before. He was revealed in Diamond, Pearl, and Platinum first, which were made way after Emerald.
You need the National Dex before you can migrate. Go to Pal Park, save the game, get the Pokemon you want to migrate in the PC, save again, play Platinum and at the menu it will say migrate from Emerald. Im the Pokemon expert. you are very lucky.
There may be something wrong with your Emerald game try resaving your game or cleaning the game pak.
you can evolve it diamond pearl platinum and later but Pokemon games before Pokemon emerald you can't. but to it evolve get a manimizer and give it to magmar and then trade it.
The Before form of the Water and Ground type Whishcash is the small Water and Ground Barboach. Barboach is only avalible in Pokemon Diamond, Pearl, Emerald, Ruby, Sapphire and Platinum
Get checked for diabetes
In Pokemon Ruby and Sapphire at the top of Sky tower after the Pokemon league emerald before the Pokemon league Diamond, Pearl and Platinum you have to migrate from the GBA Games (Sky Tower is near pfialog)
The rare Pokemon which you can get before the Elite Four in Pokemon Platinum are Giratina, Mesprit, Uxie, and Azelf.
Lucario as well as other 4th generation Pokemon were not created in any generation Pokemon game before it meaning they don't exist in Pokemon emerald or anything before Pokemon emerald.
you must get the three Pokemon reggirock reggisteel and reggice to get them you must have sapphire, ruby or emerald i don t know how you get them on there sorry but i have looked it up before
All the Pokemon from before. There are no additions or subtractions of Pokemon.