im planning to have my ipod touch replaced because it has light leaks. will they replace it with a new one even if there's some slight scratch on the back?
I'm not positive but it should be brand new. You're exchanging a new one, so you should receive a new one. Exchange it and see if there are some scratches on the back of the one you get.
Whether it's new or a refurb, it will still be scratch-less. The outside shell is replaced, and the inside electronics are tested to make sure they are in working order.