1. In lists of images, you should show thumbnails directly on the list, so people can see the images at a glance, making it easier to find exactly what they're looking for.
2. The search should just search the image tags and descriptions, but not the artist lists. Maybe there could be an artist section where people can browse all the artist info, and see all of a particular artist's work, if they so desire. But I think more often than not, people will be looking for some particular image rather than a particular artist.
Closing all openclipart bugs as openclipart is now on launchpad, as per request from Jon Philips.