I already succeeded in creating a new drawRotarySlider implementation for my plugin. It was remarkably easy which shows for me again how great the toolkit is that it does not make trivial things very difficult like I've experienced from some other GUI / code solutions in the past.
I also succeeded for a second in creating a new slider style (namely just display a integer number on a bright background when the value > 0, a little like FM8 shows in the mod matrix). This I had a problem with though since I added some binary data to the project. The IntroJucer now seems to have re-copied all JUCE modules. Is there a way to work with IJ without it erasing my work on the custom library versions?