The issue is relevant, when contolling VLC via the GUI, because it should still be responsive in order to disable repeat mode! A counter measure would be to either change the way the repeat interferes with the GUI processing or to implement a option to stop repeating after a given number of playback...
Is there an option to enable sound track decoding and playback while playing back above 4x speed?
For which reason has sound been deactivated? Is this VLC specific or codec dependent?