You can make derivative works with CC-BY-SA.

No.

No, copyright law itself restricts people from sharing code. “Open Source” or “Free Software” licenses relax those restrictions. Restrictions are never added by the license, only conditions limiting when they may be relaxed.

This is exactly why copyleft licenses are now implemented within the context of intellectual property law. You can't have a socialist biodome specifically for code.

CC-BY-SA is also not, in fact, “Open Source” because it doesn’t appear on the list of OSI-approved Open Source licenses.

Any license that prohibits modification will do. As any license that prohibits redistribution under a closed license will also do.

EDIT: "do" = to refute your statement, from which you just so vehemently distanced yourself, lmao