The oldest Pokemon games to feature Johto are Gold, Silver, and Crystal. FireRed and LeafGreen partially feature Johto after you beat the Elite Four. The newest games to feature Johto are HeartGold and SoulSilver.
You can't, but that is a good feature for future Pokemon games.
No, walking with Pokemon was introduced in the newer games; this game is old and doesn't feature that.
The Pokemon games sometimes feature Pokemon Braille puzzles. Braille is a real form of alphabet that is used by the blind.
No, this isn't a feature in the official Pokemon games.
As to my knowledge in Pokemon Diamond and Pearl there are no "hungry" Pokemon. they are like eating machines and never stop eating. the only games that feature this "full'' false reality is in all the Pokemon Mystery Dungeon Games.
Pokemon Black and White are NOT designed to have a 3D feature as some of the newer games for 3DS do. However, they look pretty 3D already :)
Pokemon White and Pokemon Black are the 5th Generation of Pokemon games. With the newest Pokemon, Zorua and Zoroark debuting in the 13th Pokemon Movie: "Phantom Pokemon Zoroark", the 5th generation of Pokemon games have finally been announced. Pokemon White and Pokemon Black are to be released in the fall of 2010 in Japan. These new games have improved visuals and a different point-of-view.
The Mystery Gift feature of Pokemon Gold, Silver, and Crystal versions is a way of communication between two games. It uses the infrared port of the Game Boy Color to trade items between games. Some of these items are unobtainable without cheats/usage of this feature. These items include: room decorations, special mail, etc.
No, the Mystery Gift feature was introduced in generation II games.
Crystal, Diamond, Pearl, Platinum, and I would imagine Gold, Silver, Heart Gold and Soul Silver.
The 5th generation region is called the Isshu region. The Isshu starters are Tsutaaja, Pokabu, and Mijumaru. The first games to feature the Isshu region and 5th generation Pokemon is called Pokemon Black and white versions in japan.