For me it sounds like syntax coloring and/or syntax checking.
I’ve seen several projects like this one around the forum, but this one is focused on
so it’s different from the others.
When I think of a mod editor, it’s right that you’ll have to write URIs and lua code all by yourself, even the json sometimes can have your own keys.
For starters, mods usually are based on adding recipes to the world, to craft your new entities. This process involves quite a few files: you have to create the entity (furniture, armor, weapon, whatever) and the recipe for the corresponding crafter. Making this is usually tedious, since it involves lots of manual renaming.
Then there’s adding classes. If it’s a crafter class it’s easy to copy existing files and modify them. If it’s a whole new class you’ll have to do code.
Adding new critters/monsters it’s relatively easy, as long as you reuse existing mixins. Then you can use those critters in your own campaigns. Of course, critters involve a lot of animations.
Other thing that modders can do is particle effects and light effects, but a user already made a nice tool for this. Also there are several topics about voxel editors in the forum, StoneVox being popular as it’s free. I haven’t seen an exporter qb->obj outside voxel editors, though…
Other than this, maybe UI related stuff, like adding something new to the HUD, but this is also more of a coding task.
Whichever features you include in the tool, I just have one advice: don’t give up