In my gallery I set up two themes, Connections and Greenflower, both modded with my Random logo with custom header file (http://forum.coppermine-gallery.net/index.php/board,82.0.html) to display, respectively, landscapes and flowers pictures I took hiking and traveling.
Now I'd like to rename themes folders to "Paesaggi" (Landscapes) and "Fiori" (Flowers), much more meaningful titles with a view to make easier for italian visitors to choose their favourite style.
Am I allowed to do this, I mean, is it legally and ethically fair?
I see no reason why you could not rename the themes so the visitors wil have a easier choice as long as the added credits are left intact.
To have a conclusive answer it might be better to contact the authors of the themes.
Legal infos about themes on authors' sites bear out your notion, so - assuming that Gizmo (who ported them to CPG) agrees as well - I finally renamed them.
I don't have a problem with users changing the names of themes as long as the credits requirements are kept intact.
As long as you only use those themes on your site and don't plan to reditribute them under a different name I can't see a legal nor ethical problem.