You miss fenris's master. Not only was fenris's sister to be freed and looked after he asked fenris permission to put in place the lyrium tattoo's.
If he was such a horrible guy why the volunteer? why would his slaves leave his side and comeback?
We know why Fenris' sister came back: She was promised an apprentice position if she helped Danarius get Fenris.
Plus Danarius apparently raped Fenris, so any argument that he isn't a horrible person is going to fall flat to most people.
No they don't, Free'd slaves go before a judge where the owner surrenders all claims and the now former slave owe's them nothing.
at any moment Templar scum could have marched in arrested or slain Willhelm at a moments notice. The guy was a war hero can could still have been sent to the tower.
Not even the king of ferelden succeeded in freeing mage's, Think about that sovereign of a country told nope.
if the Archon said a slave in tevinter was free'd anyone who tried to re enslave him would meet a very, very quick end.
They go from slave to serf, which you argued was the same thing earlier this thread.
At any moment a magister could do whatever they want to the free slave, especially since they don't have to worry about them being someone else's property anymore.
Not even the Archon who wanted to end slavery succeeded either. He was "told nope" by those under him. Some loyal citizens those magisters are.
From a governmental perspective. Same way a freeholder in Ferelden is at a Bann's, Arl's, Teryn's, King's whim. Magisters can't just grab free men off the street. They buy slaves from the 'free' nations for that. LOL
Magisters can do that if they want and think they could get away with it.
You forgot the bands of slavers they send from Tevinter to capture slaves too.