My sarcasm filter seems to be slightly faulty atm, I can't really tell which part of your question was facetious and which wasn't.

Believe it or not as you will. The entirety of my 3 part question was in earnest. I would seriously like to know the answer to those questions that you carefully avoided.

Oh, and if you were asking for my opinion on what's ethical as opposed to what's legal, it's quite simple, I try to respect an authors wishes to the best of my abilities.

I thought that the purpose of the Perlish "Artistic licence" was essentially that the author was saying

"Here it is. If it is useful to you, use it as you see fit for whatever purpose including commercial ones. Don't remove my copyright notice, and I'd appreciate attribution should you produce a derivative work."

The funny thing is that this thread started out describing technical limitations on why some corporates might be reluctant to use CPAN modules in there code-bases. These have been mostly refuted.

What you have done with your post is to provide ample reasons why I, as a former consultant architect, could never recommend that a client that they use any CPAN module, or maybe even perl itself on any commercial project. The effort required in contacting, negotiating and getting legally binding clearance from all those copyright holders would be a nightmare. Simply impossible and untenable for any company to risk having to fight legal battles in country after country all around the world as every author of every CPAN module takes your stance that they must be contacted for every use of their modules, or any derivative works arising from them, on every Perl project they undertake.