Is it possible to create AssetBundles from editor scripts from objects that are not in the scene?
Absolutely. Check out the documentation for the BuildPipeline. There is some sample code in the BuildAssetBundle method. Also check out the BuildAssetBundleExplicitAssetNames. We used this because we like to replicate something similar to file system names to prevent name collisions in the bundle like “groupone/assets” etc.