Also note that if you move your files now, you will most probably break your current world as you would need to change the link for all the maps you used.
You also said that you’re beginning to think it was a mistake. Just to be clear, when you use The Forge Importer, it will automatically upload those images to the assets library and remove them from the world folder so it doesn’t use your data quota, so you should be fine.
Personally, that’s what I’ve been using for my directory structures, though it may not be the most optimal, especially when you want the same asset in multiple worlds, it works just fine.
Note that you currently cannot move/rename files in the assets library once you upload them, though that’s what my current focus is on (see Feature Roadmap.