Embrace the scratches, they add character.
However, if you absolutely must remove them, really fine grit sandpaper (1000+ grit) can be used to "buff" them out, as well as buffing compound and a buffing wheel on a dremel or a soft cloth. Or, you can use a combination of those. Aluminum is a really soft metal, easily scratched and easily repaired.
As for customizations, you may want to hit the customization sub-forum for ideas. There are some really talented people on here who have done some amazing work, from the simple to the really complex. Though, Darth Maul and Darth Sidious both had very shiny saber hilts, especially Sidious. His was all chrome and gold. Just saying.