You can over-polish damascus and make it look very, very similar to regular carbon steel. If you finish it to all the same level, it'll look like one piece of steel. It's been etched, and the different steels eat away at different rates, that makes the layering visible and makes the pattern.
Don't rub on the sides of the blade if you can avoid it, just be sure to keep it clean and oiled. If you polish it and the lines of the pattern get hard to distinguish, you'll need to re-etch it to make them distinct again.
As to sharpening, treat it like any other knife, it should be better than most because the layered steel actually sharpens and cuts better than any other.
