The world of Thedas is loosly based on a medieval society and "freedom" was a rare thing for everbody in those times. Perhaps really only very rich and powerful men could be called "free" and even they were confined within a narrow code of conduct.
Let's take it a step further and imagine being a mage within relatively free society, a modern one. How free would you really want to be?
Everbody wants to be in control over their lives. (where to live, what kind of work to do, what sort of person to marry etc.) But even in democratic systems these choices are not as free as one would like. Material necessities, social constraints etc. do exist here as well.
On the other hand, if I was a mage, I would be worried about abominations and I would desperately want not to become one. So, a thorough education under some sort of careful supervision seems to be absolutely vital for young mages. (Connor!) Even the Dalish have the Keeper to take care of (watch?!) one or max. two apprentices.
So, mage schools, colleges etc. AND some kind of supervision, at least for young mages, are surely necessary. In the real world, and especially in western democracies (IF magic talent in itself would be accepted and not not seen as a terrible threat or disabiltiy) these schools and colleges would probably be supervised by secular boards of education. Mages would have a strong voice on these boards (but probably not the only voice! - Tevinter!) Templars would probably exist as a special branch of mage police or security, but again being controlled by secular boards, commissioners etc. They could only follow orders, not judge or punish mages themselves.
Experienced mages, mages that have proven over the years, that they can be trusted, could enjoy much greater freedoms. While still being affiliated to a local college, they could live on their own or work for other institutions or private sponsors etc.
Cases of corruption will happen (human nature being what it is) and what would happen to "fallen" mages in the real world? I am pretty sure, the mages themselves would try to get rid of these mages as swift and thoroughly as possible. If they don't, the acceptance of magic in the population would decrease and internation of all mages would probably be the next step. So, the Europeans would probably try to confine those mages for ever (tranquility even, perhaps (For their own good, of course...) and the Americans would execute them 
Still, being a mage in the real world would mean a certain amount of confinement, but probably also immense prestige and also wealth. So if I were a mage today in Germany, I would like to be educated in a well run mage college and later work for some government institution with a lot of perks and privileges. And I would not mind that I would have to report back to the head of my affiliated college to make sure, I am not possessed.
Actually, I just realized, that I sound like Vivienne (whom I do not like), but perhaps her ideas have more merit than I first thought.