Well, no point in having a laid back understated restrained Expxxxer is there?

Assuming that's all spray effects you don't want to sand it back at all or it will look horrible. Get some lacquer on it, then some more. Its not conventional to varnish rosewood fingerboards, just treat them with lemon oil or similar, but if its engineered rosewood take a good look at it. Mine had the fibres very loose and I treated it with a penetrating epoxy primer to consolidate them, then sanded then oil.

Plenty of options for decals/graphics take a look hereabouts. You can get waterslide transfer "paper" for Laser printers, which would be my choice.