The pokewaker is where you can level up you Pokemon by just walking. You can buy Pokemon only Pokemon I know is chickoreta.]You have to send your Pokemon over to your pokewaker.
No you have to re- register your poke walker at the main menu at the start of a new game
well im not entirely sure of your question but by my understandings you are asking how to get a Pokemon on ur pokewalker from an old file to a new file and all i know is you can reset the pokewalkers data by holding L+R+Down on your DS on the "connect to Pokewalker" i belive this will work hope this helps
Fortunately, if it's your Pokemon that's on the walk you are worried about you CAN retrieve it :] To get your Pokemon back, go to the pokewalker screen and hold: Up + Select + R If by any chance you get a new Pokewalker or find your old one, you will need to reset it, this can be done by connecting the pokewalker to the game and holding: Down + X + L Good luck :D
well if its heartgold soulsilver you get one bye doing a pokewaker route but the easiest way is too breed electa buzz use magmar too get magby jynx too get smocchum and so on