It sounds like the main problem is that JavLuv can't move movies unless they have a cover image. I don't see why that should be a requirement. That seems like it should be fairly easy to fix.
Beyond that, I'm not sure if this will immediately help or not, but you can always tell JavLuv not to do anything if it can't find online metadata for a movie by leaving this option unchecked:
View attachment 3573477
Also, I'm aware manually entering movie data is sort of clumsy right now (including importing a cover image), and hope I can improve that at some point. If you've got specific ideas about how to improve that, let me know. For cover images, I need to allow importing from the detail page, and I need to get copy / pasting images working properly.