will changing from scart to component improve picture ?

Most boxes don't have a component output but have a component option in the video settings. It's still the RGB signal that's coming out of the scart socket so the signal itself it not any better. Where you will see the difference is when you use high quality component video cables instead of a low quality scart cable. Even the more expensive scart cables are not as good as component. Then again, you can still get poor component cables. It all depends on what you have and what you're going to replace it with.