It can input various codes into your game, so much so that I won't bother listing them all. You'll just have to find out for yourself.
It is not dangerous. You can back up your files if your data gets deleted to restores the lost file. It's not illegal like I stated in another post.
They can be traded, if they are cloned/hacked correctly, otherwise the cheat sensor for XY/ORAS will not allow for the Pokemon to be traded.
They can battle, except for fake event Pokemon(Hoopa, Volcanion, Floette-E.) Cloned Pokemon can also battle.
http://www.datelcustomerservice.com/product_pdf/DS - ACTION REPLAY - 1.52.pdf
Yes you can, with the "A bunch of tools" code.
Yes, under "Miscellaneous Codes"