As long as the pokemon isn't Version Exclusive such as trying to trade new pokemon into older games. Example: White Kyrem/Black Kyrem trying to trade to Pokemon BW. That is invalid. However trading pokemon like Reshiram into Pokemon BW is valid.
Yes! You can do that.
when you beat the game.
Yes, you can do it. (P.S. I have done it before)
A trade is required from white or white 2 where it can be caught
Rufflet cannot be caught in Pokemon Black 2, you must trade from White 2 or White.
You cannot get it in black 2 or white 2 but you can trade it across
You cannot find Mewtwo in Pokémon Black, White, Black 2 and White 2 so you will have to trade for 1 or you will have to transfer it from a previous game.
according to serebii.net, there is no victini event in black 2 or white 2,so you need to trade from black or white.
You need to trade from white
can you TRADE for a pansear on POKEMON WHITE 2!
In Pokemon White you'd have to trade with someone who got it in Black/White 2
You can't. You'd have to transfer it from a Pokemon Black/White/Black 2/White 2 game or trade for one on the GTS.