ROBIN LANDSBERT  The sliders are just multipliers to the existing star rating. For each track I add up the star rating (0-100) and add on a value of between 0-100 for how recently it was played and then I add on another value for how many tines it was played. I then average all these values for the album star rating and average all the album star ratings for the artist star rating. The sliders then multiply these values by a percentage and propagate the values back down to their children. All you are doing with the sliders is to weight how important each attribute of a song is to you.  
(Version 1.0.1)

ROBIN LANDSBERT  Internally iTunes holds star ratings as 0-100 and will actually show 1/2 ratings if an external program (like starTunes) sends values in chunks of 10. Internally starTunes calculates star ratings as decimal pointed numbers and then rounds then to the nearest 10 when it sends the results back to iTunes. A value of 50 will show as 2 1/2 stars.  
(Version 1.0.1)

ROBIN LANDSBERT  If your iTunes database is on an external drive you will have to open the database manually as I only look in your Music folder/iTunes folder. Select Open from the file menu and navigate to your external drive. You are looking for iTunes Music Library.xml. You may need to select "All Documents" to grey in the file. Once this file is open the application should work as normal.  
(Version 1.0.1)

ROBIN LANDSBERT  Unfortunately the application framework that I am using for the tables is from 2000 (Metrowerks PowerPlant, not Cocoa) so it may look a bit dated.  
(Version 1.0)

ROBIN LANDSBERT  If you do not like the colors for each of the star ratings you can change them in the preferences dialog.  
(Version 1.0)