d
Yes
he is a starter character
play as donkey kong and beat mario 4 times without loosing 1 live In super smash flash 2 v0.8
YOu see its very weird everyone said that Donkey kong would be in v0.7 be he wasnt maybe he will be in demo v0.8 who knows?
Donkey Kong this can be tested in super smash bros but donkey kong would definetely win if you play him in brawl.
You cannot get Donkey Kong Jr. on Super Smash Bros. Brawl, but maybe you can get him on the next Super Smash Bros. game.
He is already a playable character.
unless you cheat ... no.
diddy kong
It's in the Subspace Emissary. You first have to complete it with Diddy Kong and / or Donkey Kong.
Diddy Kong is ranked higher than Donkey Kong on the official tier list. Reference: http://super-smash-bros.wikia.com/wiki/Tier_list