Pauline is not from Super Smash Bros., nor is she in it at all, other than a sticker. She is from Mother 2: Earthbound, an RPG for the N64
You don't, because the Mii isn't a playable character. The Mii, however, will be a playable character in the next Super Smash Bros. games, Super Smash Bros. for Wii U and Super Smash Bros. for Nintendo 3DS.
Yes, he will be a playable character in Super Smash Bros. for Wii U and Super Smash Bros. for Nintendo 3DS (both of which are Super Smash Bros. 4).
The fastest playable character in Super Smash Bros. Brawlis Sonic the Hedgehog.
Shadow is not a character in Super Smash Bros Brawl, unfortunately.
What character?
No, Jack Skellington is not a playable character in Super Smash Bros. Brawl.
No, Raichu is not a character in Super Smash Bros Melee and is unplayable
Dark super Sonic is not a character in Super Smash Bros Brawl.
Super Smash Bros., Super Smash Bros. Melee, Super Smash Bros. Brawl, Super Smash Bros. for Nintendo 3DS/ Super Smash Bros. for Wii U, Super Smash Bros. Ultimate.
Koopa is not an un-lockable character in Super Smash Bros Melee.
mewtwo is not in super smash bros. brawl however mew is a trophy character
Blaze is not a playable character in Super Smash Bros. Brawl, just a trophy.