I fail to understand your comparisons.
Who's an OKAY person in these scenarios:
1: The person taking a pretty girl to their first nude show after picking her up on the street promising easy cash if she just "skips class the next day"
2: The person that at her 3rd nude photo session gets her to do a BJ scene
3: The person that at her 2nd BJ scene gets her to do a hardcore scene
4: The person that at her 2nd hardcore scene gets her to take it anal
5: The person at her 2nd anal scene piss in her face
7: The person that drops her from shoots since she's burned out at the age of 25
8: The person that takes an crackwhore and pay to piss her in the face / shit in her throat and what not
If you think any of the "persons" is "OKAY" then you'd better rethink the business you are in since each step per your definition is "pushing the limits" /abuse of the person (probably with the exception of the crackwhore) and getting them ready for the next step.
I doubt a lot of people goes straight to extreme hardcore unless they are really into that kind of porn.
In either way it's an act between 2 or more consenting adults which shouldn't be judged by anyones point of view but rather if any harm is done or not, unless you live in a country ruled by Islam or similar
If you produce Scat or only shoot amateur college girls that needs quick cash for books doesn't really make a big difference, it's both pushing some personal limits of a person that may or may not be good for the society we all want to live in
