of course your gamer tag will work across the board.
I think only witcher 2 is on 360. Do you you have a computer? even if you need to play on low setting would save some hassle buying a console just for one game. If you Go to GOG.com If you meet the minimal requirements But ends up not working in the end they will give full refund in up to 30 days.
You can also go through origin, They have a "great game" return policy. You you click play you have 24 hours to return the game if you don't like the game. You also get 7 days get a refund if you never click play.