I think i need to comment on a few things that came up on the last pages:
(1) About the "earn your happy ending" principle
This is problematic because if that happy ending is one with no downsides, every other ending will appear like a failure in comparison, and you'll feel like you need to be a completionist to get a good ending. There need to be specific circumstances for this to work. One possible way is to reward a consistent pattern of choices, such as the ones leading to peace on Rannoch in ME3 or sabotaging the genophage cure without the krogan finding out. This often works, but can result in problems if players make decisions from different motivations. For instance, I am anti-krogan but I don't usually kill companions unless necessary.
For DAI, this could mean that, for instance, a consistent pattern of...hmm....let's say "pro-old-mysteries" choices (this includes the DR) results in an outcome which has no downsides if you are of that mindset and make a related final choice. On the other hand, if you play a game with a consistent pattern of...hmm... say "pro-modernity" choices (this includes a restriction of access to magic) you'll get a related good ending for someone of that mindset.
So, the "Bioware principle" of making outcomes that are good for people with a specific philosophy is still the best approach IMO, rather than one perfect outcome that always applies if you do X1, X2, etc...There does not need to be downside, since the main effects are already downside enough for anyone with a different philosophy. If this "Bioware principle" applies, there is no need for a choice "between two lesser evils".
However, outcomes like these tend to be extreme and exclude compromise, which is not always what I would wish for. Given the above examples, what if I wish for a choice where magic and modernity can coexist? If I don't want to remove access to the Fade and spirits but rather apply a modern mindset to their exploration? I will not have a satisfying ending then. If outcomes are made to appeal to specific philosophies, there will always be players left at the wayside with their preferences. Since I am usually one of those, I am somewhat skeptical even though I think this approach is the best in principle.
(2) Decisions and outcomes
In the OP, I called for less extreme plot choices. That applies to the decisions themselves, not necessarily their outcomes. I do not want to be forced to support a faction whose philosophy I disgree with. That is a roleplaying matter. A related but different matter: a decision I make for unrelated reasons results in the ascendancy of such a faction. That is not necessarily a problem because I don't control the world, but it can feel like a betrayal by the writers.
(3) The pitfalls of adding non-instrinsic downsides
As I said in (1), if the principle of making outcomes that are good from specific viewpoint is successfully implemented, there do not need to be added downsides to an outcome since the main effect is already downside enough for those who disagree. However, if a need is seen for adding downsides for other reasons, these must not be of a kind that they would taint the outcome in the eyes of those it's made for beyond redemption. Two examples: ME3's Destroy ending results in the death of the synthetics. The main group adopting this ending is the one which thinks that the Reapers need to be gone but otherwise wants things to stay more or less the same. I'm sure that most people would be fine with a big sacrifice, even of millions of people, to make that happen. However, since the sacrifice is a specific domain of life the decision acquires a decidedly anti-synthetic theme, and that is not acceptable for the majority of that group. It sends a thematic message people detest. This illustrates one possible problem with the principle of making endings for specific mindsets: if the writers fail to identify the dominant mindsets of the players (in this case, "synthetic life isn't true life" is not among the dominant mindsets), the number of players who won't get a satisfying outcome will be high.
Second example: ME3's Synthesis. This is adopted by players who think that the "melding of man and machine" is a desirable path to take. In short, a roughly transhumanist mindset. However, this is a usually extremely individualistic philosophy, and thus, the downside of forcibly changing all life in the galaxy taints this outcome specifically in the minds of those people most likely to adopt it. It is also a usually somewhat anti-religious mindset...need I say more?
These thoughts ended in the phrasing I used in the OP: For future games, I wish for a set of options that all feel as if I might want to take them depending on how I envision my character, rather than all feeling as if I might want to avoid them.