Your suggestions are based on the implicit assumption that the Chantry's ideology is rightfully dominant. That I contest.
There's nothing implicit about the Chantry being 'rightfully' dominant. It simply is. Existence is not endorsement, but ultimately only addressing reality makes real changes to, well, real conditions.
To agree to the Dalish mages having to go to the Circle, for instance, that's like - to use a current example - to give in to Turkey's demand to extradite supposed members of the Gülen movement on their say-so, with no evidence that they've done anything wrong. It would go completely against fundamental aspects of the Dalish culture.
Which 'fundamental aspect' is this? That the tribe exists to serve the Keeper? The mages are the rightful leaders of mundanes? Those might be as fundamental to the Dalish as 'it's the human's fault', but that doesn't mean it's good. On abstract, or practicality, in short term or long.
As a leadership selection strategy just in terms of leadership quality, it's stupid- mages are not inherently smarter, wiser, or more capable leaders than mundanes. In terms of history, it's somewhere between ironic and unintentional hypocratic ignorance- the Dalish, who claim to never submit again, submit to mage leaders because that's what they think they've always done, not realizing that mage-eltism was the first submission of the people. Practically and ideologically, the premise that some people deserve to boss around The People just because of an accident of birth is something that easily deserves to be questioned.
And that's just internally. What does that cultural practice do externally? It antagonizes the very people whose tolerance the Dalish clans need to survive. It creates a constant tension which leaves the proud people fleeing for their safety on a constant basis. It's one of the biggest reasons they can't establish enclaves and re-establish the sort of society that would do far better at preserving elven history and other cultural practices. The Ancient Elves weren't nomads, so the Dalish are always going to have to give up their current way of life anyway even in the most ideal circumstances.
The Dalish culture isn't The Way Things Should Be Always. It always is, always was, and inevitably would change. If it's going to change, it would absolutely be worth considering the deliberate ways it could change that might actually benefit the Dalish. Changing a mediocre leadership that primarily exists 'because that's how it's always been done' is absolutely worth considering, if only to decide what, exactly, about it is worth preserving.
That's why I threw out a spectrum of things that could be considered, not a single proposal I'm positing as The Way. Obviously most of them will be rejected- though whether those rejections are wise is a separate thing..Ditching mages entirely would certainly be radical- but the point isn't that the Dalish would, but that they could, and that there could be real benefits from such a cultural change.
Any compromise that deserves the name has to treat the two cultures as equally valid, to start with (not that I think either one is particularly worth defending, but that's a different story). To agree to stop killing or imprisoning each other would be a good first step, along with visiting rights into the other's territory (not by armies, of course) in order to get to know each other better. Cultural contact, that would be the way to co-existence. The implicit assumption of superiority has to stop, on *both* sides.
Enjoy watching the Dalish decline on the way to extinction, then, because the two cultures aren't on equal footing.
One is established, well organized, militarily robust, has a dynamic political system both capable of conducting negotiations and better equipped at fulfilling them, is growing in capability and influence over time, and finally is secure enough in its position that the situation is a minor concern, not an existential threat. The other the Dalish, who are in a decline in nearly every respect. The two groups can not compromise as equal if they are not equal in every politically relevant category.
The Dalish need things to change more. The Dalish need an improvement in relations more. The Dalish are in far greater danger if the negotiations do not pan out. The Dalish are asking for far more, and already have far less to offer. For the Chantry and Andrastian nations, this is handling a minor and occasional nuissance: for the Dalish, relations with the Chantry are an existential subject.
The negotiating positions are not equal, and preconditioning relations on the pretense that they will be will accomplish nothing.
Agreeing to cultural contact would be a big step for the Dalish given their present stance, and especially since they're the less powerful culture. The other side has to recognize that. What comes of that, who knows?
Relative effort on your part is irrelevant unless it corresponds to a relevant impact on the other party's part. Someone who struggles on something that offers very little benefit to the other party isn't going to impress anyone into making significant concessions.
If you want trade with someone, you have to give them something that they want- not something that's hard for your to deliver. Whether it's hard for you to deliver or not is irrelevant to their vaulation of it.
Maybe the Dalish will have to stay in remote regions in the end, maybe not, but I see no justification for a demand to submit to Chantry rules regarding mages, except perhaps for the surplus mages who would otherwise be cast out. As for their system of rulership, it isn't any worse than any other system on Thedas.
The justification for considering is is 'survival of the Dalish as a relevant polity within Andrastian lands, so that they can represent the True Elfy Way for all elves in the future.
If the Dalish exile themselves outside Andrastian lands, they won't be leading or bringing in the city elves. If the Dalish succumb to fragmentation, they won't maintain the True Elfy Way. If the Dalish refuse reconciliation and instead remain in opposition, attrition, or even face outright eradication later, the Dalish will be dead and there will be no True Elfy Way and no Elfy Alternative for the city elves at all.
Dalish culture needs to change to save itself. If it refuses to change itself, it's just trapping itself in its current downward trajectory.
That you change how you select your rulers as demanded by someone else is actually a most significant indication of submission. It's about the last thing any culture would agree to.
It's also one of the most important things to consider, because how you select your leaders determines how you establish your elites, and the wrong sort of elites can be far more ruinous for the culture. Elites should take actions for the culture as a whole- the culture shouldn't be built around protecting the elites.
If the Dalish can make a strong argument on the merits of a Mage-Keeper system, that's fine- but they can only do that if the pros and the cons are considered. So far the pros have been 'that's how they always do it,' 'change is bad,' and 'mages are more more worthy.'
Forgive me if I find none of those particularly laudable.