Custom items?

At the moment, is there a way to make a custom items?

For example if I made a lantern model in blender, could I import it to rust?

No, as of now you cannot.

^ Also that’s their last priority now, with the game being in alpha. So don’t expect it for a while.

Allowing these as ‘decorative’ pieces early on might actually be a good thing. Many games (especially sandbox games) tend to live or die on the modding community.