Answer to: Why when my iPod is being charged the backlight shuts off?It's most likely the connector from the LCD being loose and not firmly attached. When plugging them in it usually is supposed to make 2 clicks snapping it into place. Update: To clarify, the LCD ribbon connecting to the logic board is what I'm talking about.
Answer to: Black stuff scratched inside screen, how to fix?No do not try to scrape off paint from another screen. Just go over it with a black Sharpie a couple of times (waiting for it to dry each time) and make sure it's dry completely before you apply it to adhesive. If you get too much on the area you can even it out with a Q-tip dipped in some Rubbing Alcohol.