I assume you are running your show from a computer and not a director. My comments assume that to be the case.
1) You can run the Visualizer and see exactly what is going on. It’s very easy to do that on the show computer, and fairly easy to do it on another computer that is on your same LAN. With a little effort, you can even run the Visualizer anywhere on the internet with a little advanced planning - I have done it.
2) There is no way to abort a currently running song and skip to the next song. However you might want to look at MIIP which lets you (or anyone else), change the order of songs. Search here on the forum for MIIP and you’ll find it. If you want to see what it looks like, go to wfcl.miip.mobi and you can see what’s playing on my show and change the order. Obviously you can’t actually see my show unless you happen to be in Glendora, CA.
3) What issue do you have with the calendar?
4) When you start a Show on Demand, if you give an ending time, it will stop at that time and if there scheduled show, the scheduled show will start. If you don’t give an ending time (the box for run it until you tell it to stop), what do you expect it to do - read your mind that you want it to stop?