Functional expressions are not copyrightable. If I own a copy of the code you wrote, I am reasonably allowed to extract those purely functional expressions into my own work. Purely creative expressions are still protected by copyright. (This is why you cannot copyright an encryption key.)
When no “owner” exists, the licensing agreement is no longer valid. Copyright is a different issue. See above.
If I bought the system, I bought the code.
Functional expressions are not copyrightable. If I own a copy of the code you wrote, I am reasonably allowed to extract those purely functional expressions into my own work. Purely creative expressions are still protected by copyright. (This is why you cannot copyright an encryption key.)
When no “owner” exists, the licensing agreement is no longer valid. Copyright is a different issue. See above.