If you want something to be always imported, copy the Wurst.wurst file from stdlib, then edit it to include imports you need. That way, the Wurst.wurst from stdlib will be overwritten in your project, and default imports will be changed.
Oh, and also, if you want to save IDs, you should do this:
https://bin.wurstlang.org/okaduyexoz.wurst
The alternative is having actual object wrappers for this kind of thing, and having an elaborate definition framework, but that's way more complex.
Also, "import public" means that when A imports B publicly, C that imports A also imports B directly, meaning you can import LinkedList to some package publicly, then have another package import that package, and also have the access to all LinkedList functionalities.