But can they be free and not be rulers?
Rivain, regardless of how it is ruled, because no it isn't "obvious" one way or another, indicates otherwise.
Sure they can. And even if some mages end up in a position of influence, why would that automatically necessitate disaster?
Sure, one or two Seers may end up in a position of influence that may or may not direct the local villages, larger settlements or even possibly the country itself, but the very nature of being a mage or a Seer is not an immediate disqualifier about their capacity to rule. What does or does not, or more realistically, what should and should not qualify a person for a position of power is not their abilities but their willingness to use that power at various levels. A person in any level of authority has the potential to abuse their power. Howe being a prime example. He purged an alienage, slaughtered an entire family to claim a teyrnir, embezzled silver from the treasury during wartime, hired miscreants and criminals to be part of the city watch, tortured fellow nobles and political opponents and so on and he didn't have an ounce of magic in his veins.
Does that mean that every Howe is going to be the same by virtue of being a Howe? If Nathanial is ever in a position of power or authority, what's to stop him from becoming another Rendon Howe? The answer is simple. Himself.
Sure, you can make an argument using the lore that the Rivaini's aren't ruled by mages, but to a certain extent are governed by them, but this does not have to be a bad thing because the ones who are doing the advising or making decisions may or may not have magic.
It only becomes a bad thing when the person in charge starts making decisions that affects the country, its citizens and people negatively. You don't have to be a mage for that to happen.
Like yourself?
Expect the norm or don't either way it's conjecture.
Hence why I said my theory was based on all the lore established. And what is established is straightforward.
1. Rivain is an exception to the Circle systems because of the widespread support of mages and the Seers, who have a respected place in society.
2. The Seers allow themselves to be possessed by Spirits (not necessarily demons.)
3. Abominations are rare in Rivain, and when they do happen, it's treated as a natural disaster and not the fault of the mage itself.
4. Mage freely associate with their families.
5. Mages associating with their families and that some mages are trained as seers is why the Circle, the one with the most exceptions, was annulled, and it was not popular with the people.
6. There is no confirmed widescale blood magic or slavery.
"It is a mistake to form theories before we have the facts. Inevitably we try to twist the fact to fit our theories rather than twist our theories to fit the facts." (Sherlock Holmes.)
As such, based on the evidence we have of Rivain, it is logical to come to the conclusion that Rivain is not the same as Tevinter, does not have many abominations despite mages willingly allowing themselves to be possessed, had a Circle in name only, and some paranoid zealots in the Seekers and Templars didn't like it.
If Rivain was having more problems, it would be established. Like Tevinter and its hypocrisy on blood magic and it being a slaving nation, the Anderfels and how the Wardens practically run things, Orlais and its issues with "the game" and the huge disconnect between the rights of the nobility and military (chevaliers) compared to the commoners, or the Free Marches being a city of City States and isn't an actual country.
You're right in saying that my conclusion is ultimately conjecture, but my conjecture is based on established facts and lore, and nothing in any of it does anything to contradict my argument, as such my opinion about Rivain's society and how I see it holds a lot of water and doesn't have any holes beyond "it's just conjecture." If more evidence comes out later about how Rivain works, then I'll once again have to adjust my theory to fit the facts.
Not at all because Seekers only had their minds touched by spirits, they were never possessed. Seers are posses which is dangerous regardless of how benevolent one might consider spirits to be. Anders proved as much.
Also, just because people feel attached to a culture, it doesn't mean it is even beneficial for them. Of course, whether we will consider to be beneficial will be influenced by our own culture.
At any rate, popularity doesn't equal being right.
Anders proved how corrupting an influence can be on a spirit, and Solas proves that if you remove such corrupting influences then you can have rare and powerful spirits as great friends with his personal quest and the spirit of wisdom.
I'm not saying Anders is right or wrong, especially since I usually execute him, but what I am saying is that there is no "one-size-fits-all" definition of spirit possession. Anders and Wynne both prove this, heck Flemeth/Mythal alone is an extremely unique situation.
And I didn't say that Seekers were possessed, I said that if you denounce affiliation with spirits or thinking you can control them, then you ought to denounce the Seekers because of their long-term use of Fade Spirits being used to cure tranquility. How is that particular spirit called? How is it convinced to touch the mind of the tranquilized seeker-to-be? How is it controlled if it is not persuaded? These are questions that the Seekers under Cassandra must answer. The implications of such are quite staggering to be honest. Because it shows us that the Seekers, even if they aren't possessed, are summoning spirits.
If your response is that Seekers have a long tradition with few disasters as proof of their capability, then I would respond by saying so do the Seers according to the lore.
Without more information on how Rivaini Seers actually are, and the nature of their possession, it is impossible to write them all off as abominations, and that is my argument.
And you're right that popular doesn't mean right, but there is no evidence that even suggests that the Rivaini's are wrong beyond what we expect of possessed mages. But since mages being possessed has so many varieties and even that may change based on the nature of a spirit, then it is impossible to judge the Seers based on the information we have now.