You're supposed to goto Mt. Coronet I think and get to the summit, you have to go through the Heartthome side...
you have to battle Giratina in distortion world and then you can battle them
yes for r4 you can download it but i dont know if the pc one is three
you don't
You can get it for free if you steal it.
no
Yes its free.
Yes
You can't
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 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.
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.
maybe at like walmart like they did with diamond and perl