Yes, it is possible to trade your UK Pokemon from Diamond into the Japanese Pokemon Black version. However, you need to beat the whole game in Pokemon Black & White to be able to trade Pokemon from the other generations.
Yes, the Mew distribution from January-February is only for the Japanese versions of Diamond, Pearl, Platinum, HeartGold and SoulSilver.
You need a AR, the glitch is only in the early versions of the Japanese Diamond/Pearl.
Glaceon is a Pokémon that is exclusive to the Diamond and Pearl versions, and it's also not possible to trade them to the Leaf Green version, so, it's not possible to get that Pokémon unless you have de Diamond or Pearl versions.
it doesn't happen, there is no glitch, it only happens in the Japanese versions. Plus, if you get an action replay, you can get him and all the other legendarys.
You may be thinking of a Herkimer diamond, which is quartz, not diamond.
No you need action replay or migrate from fire red or one of the other game boy games
The Japanese translation for dark stone in the American versions of the game was dusk stone. The dusk stone cannot be found in games prior to Pokemon Diamond, Pearl, and Platinum.
Celebii is not catchable in Pokemon diamond. You have to transfer it in to Diamond from other versions that have Celebii in it.
Trade them from the Diamond and Pearl versions.
You have to trade with the Diamond and Pearl Versions.
Diamond and Pearl versions
Leafgreen and Firered, Pearl and Diamond