Nice crisp picture, I think you did fine. I personally like to inspect every mark and crevass on the coin's surface, so I do prefer a slightly larger pic. That's just my personal preference, though. I wish I could get that clarity on mine, I use a Sony DSC-H5 w/macro built in, and it does pretty well overall but not quite the crispness of yours.
Do you mean the shadows around the outside, away from the actual coin, that run about 4-7:00 around the perimeter? I don't mind them at all, but if you wanted to you could lay out a background and crop each coin and paste them to it. I use Photoscape (free) to crop coin pics and insert a solid background. It's not a fancy as Stef's templates, but it removes any background distractions.edited to try to clarify