The positive and negative aspects can be different for different participants for the same externality. Externality literally just means impacts not captured in the transaction.

Exploitation is orthogonal. You can have internal or external value exchange that is exploitative. You can even have positive sum transactions that are exploitative.

It must be exhausting having conversations in your circles if you change the definition of all the words…

Some words are just useless pandering, and conversations become a lot easier when you omit them. Some theories as well like to invent stuff like epicycles rather then question the underling assumptions (e.g. of circular orbits with the earth in its center), when you start to question the need for such epicycles you may just discover that your underlying assumptions were just wrong this whole time.