[@Lucius Cypher]: A few things I have to point out:

If one of his parents wasn't a Nem, he'd be half-Nem. This is possible, but can be risky for the mother due to potential birth complications.

Backstory-wise, I have to point out that merchants wouldn't be in charge of noble ransoms, and that, as laid out in the OP, open slavery is aggressively hunted down by the Church(and is illegal in the nations we'll be primarily focusing on) and thus would be more of an underground secret kind of thing.

[@Crimson Paladin]: Accepted.

[@Raineh Daze]: Accepted.

For everyone else, eager to see what you come up with!