Question

I know you can't send pokemon that are only in 2 back to 1, but can you send say... Emolga from 2 back to 1?

Answer 1

Currently trading information is unrevealed (apart from the obvious stuff like trading Black Kyurem to the first game). Though you can expect info soon, as B/W 2 have been released in Japan earlier this week, and so info will spill like crazy in the coming few weeks.