I just started using YACReader and I'm trying to move comics to other folders using it but it doesn't seem to be able to do it. I assumed it was possible but is it not? I'm using Win10 so I'm not sure if that may be causing a problem.

Although I can make a new folder using YACLibrary and it says to drag folders and comics to it, it won't accept anything from either YACLibrary or the Window Explorer, so I'm not sure what it's there for. Just a placeholder for future features?

You can drag&drop folders and comics from Windows Explorer (I have tested this right now). Drag&drop within the app is only allowed in the reading lists section.