you don't
no you cannot
You can get it for free if you steal it.
if you want to get lots of money well,do the Pokemon league
no
Yes its free.
Yes
The Champion probably
I battle
You can't
There is no legal way to play Pokemon Platinum online for free. You need to purchase or rent the game on Nintendo DS or borrow the game from someone you know who is willing to lend it to you.
You can't get Misdreavus in Pokemon Platinum, you have to trade it through Wi-Fi or get it from someone who has Pokemon Pearl. If Pokemon Pearl can't be found, go to McDonald's as they have free Wi-Fi.
There are currently no working DS roms or emulators, but if you want, try searching Google for a DS Emulation with Pokemon Platinum ROM also.