If I use Dragonair's "Dragon's Wish" attack and then on the following turn evolve it to Dragonite, can I still attach the energies or not?
Yes, absolutely! The Dragon's Wish effect resides on the player, not on the Pokemon.
Dragon's Wish




x2
Dragon's WishDuring your next turn, you may attach any number of Energy cards from your hand to your Pokémon.


Tail SmackIf I use Dragonair's "Dragon's Wish" attack and then on the following turn evolve it to Dragonite, can I still attach the energies or not?
Yes, absolutely! The Dragon's Wish effect resides on the player, not on the Pokemon.
On the turn after using Dragonair's "Dragon's Wish" attack, when I attach any number of Energy cards from my hand do I have to attach them all at once, or can I attach them whenever I want during my turn?
You do not have to attach them all at once. You can attach them from your hand whenever you like during the duration of your turn following Dragon's Wish.