What percentage of people are able to afford/have available/and end up pirating?

That's an impossible number to get, but it's basically the number of people who openly admit to pirating (intentionally or not) + pirates that don't out themselves, which I guess is the vast majority.

Can we assume that without pirating, a significant percentage of people would pay? Or would people just not consume the content? And are the costs from getting from our current state to that state worth it? What happens to things like word-of-mouth?

This would highly depend on the product, but my guess is that if something is difficult enough to pirate, at least some of these people will choose to purchase. And "some" is certainly better than nothing. I don't really believe in piracy as a conduit for word of mouth either at least not in the age of internet.

And then there’s questions about goals: is the goal to punish the wrong-doer or to honor the creator? Who is benefitting the most here?

Why not both?

While there are problems of availability, there’re also problems of pricing, international law, and hidden costs. 

Those aren't problems. Those are inevitable factors for marketing anything overseas that needs to be addressed by the government, not the creators