For scratches, as long as you can't get your finger nail into them, I use G3 cutting compound with a waffle foam pad on a random orbit DA, I always wet the pad 1st with water and go very easy, scratches come out in literally minutes, I then finish with the G10 finishing compound again with foam pad again wetted 1st on the same DA.
For me the trick is to take your time, use a wet pad as it works better and keep checking your work, you soon figure out how long it takes to lift off the marks you want rid off.
For me the trick is to take your time, use a wet pad as it works better and keep checking your work, you soon figure out how long it takes to lift off the marks you want rid off.