There are a lot of fixed rules around importing and creating packages.
I think packages should be much more simpler, i.e. no need for comparing Guids/Project Ids or anything like that. It should be as simple as selecting import and the files being overwritten!
1. In order to create project packages, you need to set the "Assign To". I think it should be allowed to create Project Packages with leaving this option blank.
2. You are only allowed to create Return Packages if the project was a received Project Package. Allow Return Packages all the time without any limitations.
Use Case: Recreate the project due to issues with the original received Project Package
3. You cannot import Project Packages if you publish the project to Groupshare. I would like to see compatibility between packages and Groupshare.
4. Allow re-importing packages you have already imported.
Reference:
https://community.sdl.com/solutions/language/translationproductivity/f/92/t/13310