It's unclear who invented the circles, all we know is when Tevinter turned to worship Andraste, the Magisters Surrendered themselves to the circle (own there own terms)
today the imperial towers operate very differently to towers throughout the rest of thedas, You do not HAVE to be part of a circle there is no such requirement. in fact circle's in Tevinter are a privilege to attend, not an prison where mage's are kept indefinitely. Mage's can keep family leave when they like and in Templars answer are Protecters, they still have the rights of annulments and step in when things get out of hand, but it quite clear that it is Mage's themselves that set the rules for templars not the chantry.
the changes to the chant of light came AFTER the Orlesian chantry found out about the fact a Man who was also a MAGE was in charge of the imperial chantry, he needed to justify his rule. The changes were made to reflect the Idea that Mage rule was the devine word of andraste.
people enjoy pointing out the permitted use of blood magic in Tevinter, like slavery and the fact that for the most part the archron is a figure head rather then a leader, But such arguments are Irrelevant, they are problems with the political system with Tevinter, not the circle in and of itself.
the fact is the circle system in Tevinter clearly has no issue with uprising's or abominations running wild Tevinter could not possibly have stood in the face of exalted marches, blights and invasions by the followers of the Qun if this was the case. People can speculate all the want about what might happen the fact is, magic is welcomed and indeed honoured throughout Tevinter. People don't needlessly fear magic and Mage's have as much freedom as all Freemen in Tevinter.
to suggest Tevinters circles breed blood magic is incorrect, Blood magic is still officially outlawed it is rampant in the upper classes due to the corrupt way Tevinter operates the upper classes are above the law.
the Rest of thedas is no different, The upper classes can murder and rape with immunity.
I'm not suggesting a mageocary like tevinter far from it, only that quite clearly Tevinter circles are much better run. your argument makes well not alot of sense I'm not asking to implement tevinters political system only the circle system. you can still ban mages from government and give them the freedoms of the circles in Tevinter at the same time.
the fact remains what the orlesian chantry declare about magic is superstitious and does not reflect the words of andraste it is quite clear magic must be used to help people, that doesn't equate to locking people up! and theres nothing in andrastes teaching that say's so. the chantry KNOW this but teach otherwise.
Actually no, we know that the Tevinter Magisters invented the circles first. The Chantry copied off of them.
ACtually yes, you are required to be a member of the circle they just don't mean you are locked up in one.
Considering the Mages are the Imperial Chantry, the mages or the chantry telling the templars what to do is the same thing.
The changes to the chant came before the black divine. The changes were actually made within a few generations of Tevinter converting to Andrastianism. They reflect the cultural difference between Tevinter and southern Thedas. Tevinter heros are all mages and the entire society is built on magic. For a generation or two the mages were not allowed to be in the clergy or hold power, but that quickly no longer became the case.
Actually the Imperial chantry considers Andraste 3rd behind the Maker and the Archon who converted them to andraste. It has nothing to do with making it divine.
If the black divine and all magisters in Tevinter pretty much practice blood magic, it is an issue for the Imperial chantry considering their very religious leader practices something his own religion bans-that is the imperial chantry.
The fact that they have templars and rights of annulment(your own word) indicates that abominations are still an issue in Tevinter.
Actually Mages and their families are basically the only freemen in Tevinter. If you don't come from a mage family you can't hold political office or positions of leadership in the Imperial Chantry. Nor can you be the black divine as he is always chosen from among the 1st enchanters of the circles.
No, Blood magic is practiced in the pursuit of power and because most tenvinter heros used blood magic. It is a cultural thing. That doesn't excuse it.
ACtually we have no idea on what the actual teachings of Andraste were. We know the chant of light which both the imperial chantry and the orlesian chantry originally had the same way. All evidence we currently have leads us annectodotally to believe that that is the correct interpretation.
And considering it has been 900 or so years since Andraste and the founding of the chantry that occurred after her death, I am fairly certain the Chantry is no longer aware of a coverup if there is one. The current divine and revered mothers have as much knowledge of the early chantry as I do the private musings of William Duke of Normandy.
The World of Thedas is a good read. You should pick it up.