What are the restrictions on transfering from Pokemon Bank, and do I need to recapture my Pokemon?

Question

First, can I transfer Pokemon from Platinum to White using the bank without doing anything special? Like beating the Elite 4 or whatever?
Second, will all my items transfer ok? Like evolution items, power enhancers, master balls & items that belong to legendary Pokemon only? (Ex: lustrous orb)
Third, will I need to recapture any of my Pokemon? Legendary included?
Finally, which is more compatible, 2DS XL OR 3DS?

Comments

For future reference, you should ask separate questions in separate threads. For example, the fourth question here doesn't have much to do with the first question.
e: updated the title to something that mostly captures the questions

Answer 1

1: In Platinum you don't have to beat the E4, but in White you do, as the Poke Transfer Lab is in a post game location. Pokemon Bank is not used to transfer from Gen 4 to Gen 5, but instead uses a pre-installed app on the 3DS called "DS Download Play." Here is a tutorial for how to transfer from Gen 4 to Gen 5.

2: Held items can only be traded, not transferred. Any held items of Pokemon you transfer will be sent back to the bag of the game that they were transferring from.

3: Pokemon aren't copied when you transfer them. If you transfer a one-time-catch Legendary out of a game, it is unobtainable forever in that game, unless you reset it. Any Pokemon you transfer will need to be caught again if you wish to still have one.

4: Any console in the 3DS family is compatible with Pokemon Bank. I'll also say that in order to transfer from Gen 5 to Pokemon Bank, you need to download Poke Transporter on your 3DS, which is a free app.

Hope I could help! If you have any more questions, please ask!