Thank you for the details. The video ratio effectively needs to be fixed. The audio input selection would be a good addition.
The fact that the audio tracks start grey is on purpose. When greyed they are not loaded in memory. If you have a big sound library you don't want to load them all at the start of the software. This allows you to load only the sounds you will want to play. Then you can play them as much as you want with fast reaction time. I tried other solutions like streaming them from the disk but it was not responsive enough and caused performance issues. Note that you can load all the sounds of a page with the button on the top left of the page (an arrow going in a cube) or through the keyboard key [alt-gr]