Thanks vaateri .

1. Localizations would be possible since it is supported by the QT framework. It isn't anything that I have looked into it yet though.
2. Unlike other requests to the Squeezebox server, the result list for favorites doesn't contain links to icons. Therefore favorite icons aren't shown. However, I can see that e.g. the web interface has icons presented, so I will try to find a solution for Squeezster as well.