Its a complicated issue that I have no idea what to do about. There are the matters of mods being uploaded with no permission and there are the matters of this being even more of a hassle. Perhaps there is not a perfect solution but instead a compromise that can increase protections of mods from being uploaded without permission but with not too high hassle. Maybe require ports to list a way to contact the original author?
No source just means it can no longer tell you where it came from or notify you of updates. You might be able to add it back in in the menu you open when you double click it.
Just make what ever you want, but keep it simple enough you don't get overwhelmed, Like I started out with ports and mods that changed armor ratings to my liking, and here I am making the same types of mods :laugh:
To add a game quickly, other than making a new extension yourself, would be to use the extension called "Add Game Wizard" to add it, it would work as long as there is only one directory used for those mods.