AFAIK, this comes with distribution limitations like to your department and students in the university. There's an exception for arXiv generally for publishing intermediate revisions, but not the final one.

Elsevier has a nice summary at [0]. At the bottom there's "Publicly share the final published article". It's "YES" for Open Access and "NO" for subscription (classical) model. There's a rather detailed "Scholarly Share" which allows sharing with researchers, but not to any researcher, as I aforementioned on top.

[0]: https://www.elsevier.com/about/policies-and-standards/copyri...

Sometimes yes, sometimes no. In my case, the edited versions of (my) paper had more experiments, refined images and was more complete.

The paper was not bad to begin with, but the edited/revised version painted a more complete picture which shouldn't be possible without a set of external reviewers.