Breed a female starter
No. The starters are still : piplup, chimchar and turtwig.
No. You can only get 1
There isn't a second set of starters.
Obtain 200 Pokemon in Pokemon ruby, sapphire or emerald, then go to professor birch and you get to choose one of the johto starters, then you migrate the starter you chose to Pokemon, diamond, pearl, or platinum.
The only way to get the Sinnoh starters in Pokemon HG/SS is to trade it from games Diamond, Pearl, and Platinum.
Some Pokemon are able to walk in amiti square, but in platinum even starters and there evolved forms can walk with you.
All the starters are equally good.
That's impossible.
no because you can die
You can't find Turtwig in the wild. You have to choose it from the starters Pokemon.
Cynthia (Pokemon Champ) will give you the eggs every once in a while.
Its impossible to see the starters from kanto in platinum you must migrate each Pokemon from firered/leafgreen to platinum to receive them.