End of november, there will be a patch to solve the graphical performance you see with Retina display.
In the mean time, running in low-res is the solution.
is there a way to add an option to render only the waveform like it was before (low-res-mode) and render only the text with Retina-Mode?
Not such an option. I will need more votes to consider this.
Also is there a way to add the Clip-Color-Function into the Clip-Context-Menu again? The way into the Ribbonmenu is to large and shortcuts is not my style in this case…
No option currently. But you should reconsider the built-in shortcuts. Rather easy.
Another nice feature i would wish is to have an option to make the ui-text larger or user-definable… the choosen fontsizes is for my taste a little to small and i would like to set it larger…
The problem with font customizing, is that it leads to many more stuff to adjust and test from the programming point of view (space issues). IOW, this is an expensive feature.