If the scratches aren't causing a problem now, they won't, the only time a scrtach causes a problem is when it's over the whole sector, or you either deepended it in some way or it grew.
Now I would be careful with those disk and make sure they don't get any other scratches and if you want to try and get rid of them, go ahead and get one of those automatic cleaning and repair DVD repairs, don't get the manual one as they are a pain to keep a a solid pace without slipping or stopping and it's not because of your arm it's because of the way the are build and sometime the gears slip and you don't have your even rythem any more.
I have repairer and I love it. I have yet to find a disk that I can't repair with it. It took one disk that would not play at all, I srayed it like the directions said, put it in my repairer, hit the button, it spun the disk around less then a minute I dried it off really good and it's now plays like brand new. It saves a ton of money, as now I dont' have to buy a brand new disk every time one gets scratched. As when you have a cat who loves to knock everything off or over, some DVD cases just are not made to crash to the floor and keep the DVD in place.
Good luck, though I do hope that sounds works out for you, that would be a bummer if it ruin the sound.
Kit