This plugin checks how many Diggs an article has, and shows a "Digg This" badge if it already has 10 Diggs.
In future versions, this will be added as an option to the plug-in in your dashboard. In the meantime, you can manually change this value in the "check-digg-stats.php" page.
Look for the declaration of $minDiggs. It should be set to 10. Change '10' to whatever value you want to use as a benchmark.
Sure. This article on PHP image functions has enough Diggs to get a badge.
If you have a problem, question, or feature request, you can send them my way and I'll deal with them when I have the time.
The easiest way would be to go to the plug-in homepage and leave a comment.