You know, I think I have two basic questions for people proposing their own alternatives to the Circle system:
'How would you prevent an effort to turn your system into a Tevinter mageocracy?'
and
'How would you handle someone like Anders?'
Cause, when you get down to it, Anders very much strikes me as the sort of person who would find something to rebel again. It doesn't matter how light you feel your restrictions are, it would be too much for someone like him who doesn't accept any such restrictions at all.
At which point, 'seven-time escapee and determined to bring you down' strikes me as a relevant thing to be concerned with enduring.
1. In order to keep free mages from making a tevinter magocracy? For one thing I'd keep the templars around and kill corrupt mages who use blood magic without templar supervision and kill every demon I came across who are not in the Fade. And even then I might just kill all the demons I can while in the Fade if I'm playing as a mage.
There's a place for templars. Add in that the templars in Tevinter don't take lyrium and don't have the ability to negate magic kind of takes away the dampener on mages that everywhere else has.
I'd also say mages can't inherit a title. I have no problems with them being involved in court. My mage warden is the Chancellor after all. But I'm not the king. My biggest issues with the circle is the lack of rights mages have like having families, not being allowed to get married unless they get very special permission and even then they aren't allowed to keep their children.
I'd also require all mages to attend the Circle at least until they passed their Harrowing or some version thereof. And despite the fact that I find the Right of Tranquility absolutely abominable, the tranquil can handle lyrium far more safely than regular mages so they naturally are better suited for enchanting services, so I wouldn't get rid of it, but I would limit it to be used as punishment on blood mages and mages who abuse their power. I'm sort of like the Qunari in that I don't believe in wasting resources and people are resources, even if it isn't politically correct to think of them as such.
Templars have a place in watching mages and looking for signs of corruption. They are trained for this and this is something that must be handled. I'd just reform their order so that they are held accountable and to higher standards. Templars won't become Seekers. Ever. You run the risk of Seekers trying to become more like templars and observe mages rather than be the templars internal affairs office and observe templars. The Seekers would be recruited largely from highly skilled city guards like Aveline, officers in the military, or talented individuals, and they won't be held accountable to the Chantry but to some politically neutral organization, say the Inquisition. Or at least maybe just a branch of the Inquisition that focuses on templars only, while other parts of the Inquisition focuses on other issues.
2. How would I handle Anders?
Well, first if he's running a free clinic in my city, I'd set him up in better accommodations and make sure he has everything he needs, supplies, personnel and so on to treat as many refugees as he can. If he's blowing up religious buildings, then I'd have him arrested, put in a very public trial, and have him either made tranquil or executed and make it very clear that he's the guilty party. Given his possession, it would likely be execution. The Circle would be on high alert and I'd probably have the Inquisition come in and run a search of it while the templars locked down facilities to keep civilians out of the circle until the whole mess was handled. Make sure there are no supporters, potential copy-cats or blood mages, etc.
After the incident passes, the circle would go back to business as usual.