I'm sorry to rain on the "I love appearance-changing mods" parade, but I don't believe in messing with art.
It's visual symbolism. The devs put a lot of time and effort to make the characters' outward appearances reflect their innermost personalities, worldviews, etc.
For example, in DAO the devs gave Alistair a crew cut which signifies his straight-laced attitude about duty, and a clean-shaven face except a little speck of beard on his chin to show how boyish he is despite his age. Then I see people modding him with ponytails and stubble, which signifies a more loose and mature personality, and I think, "That's not how Alistair is as a person, and this mod covers that up." (DAA ANDERS had a ponytail and stubble, which showed how much more loose, laid back, and liberal he was.) Morrigan had a tight bun, which signified how uptight and high-strung she was. Guess what? Tons of "DAO Morrigan wears her hair loose" mods, but Morrigan is not a laid back or loose person.
It's like that with DAI, only arguably moreso. The devs specifically said they worked tirelessly (and went through many drafts) to make each characters' appearance, outfits, hair styles, etc. reflect their innermost personalities. Sera's hair and clothes are loose, motley, mis-matched, and disheveled to show how much of a careless urchin she is. Dorian wears tons of flare and flash (and a spiffy mustache) to show how flashy and confident he is. Solas has that "hobo apostate" look because he does indeed live like a hobo; his clothes are also plain and understated to highlight how mild and unassuming he likes to present himself as, and his baldness is meant to connotate ageless wisdom.
I don't like mods that mess with their appearance because (to me) it feels like changing art. It feels like the person has decided that their vision of the character is better than the artist's , and they're denying how the character is by changing the their appearance to reflect the persona they want as opposed to the persona the character actually has.
I also agree with you on this. For me personally, I steer clear of most mods for Dragon Age simply because I feel it would disrupt the 'lore' for me. You really hit the nail on the head with everything you've said. I feel exactly the same way. That isn't to say I hold anything against those who do use mods. To each their own. If they use mods and get enjoyment out of it, then I'm happy for them. I'm glad that they're delighting themselves. Plus, I really have nothing against mods that better performance, fix bugs, and alter things to a better state. A good example is that eyebrow mod I've heard so much about. It doesn't change the overall appearance of anyone; it just fixed the eyebrows to be, from what I've seen, more realistic. That's just an example of many. As I said, I have no problems with others using mods that affect various areas. x3 Just for me personally, I like to use as few as possible.
And as for artwork being the same thing, I agree with Delphine. But I suppose it really depends how you look at it. I don't regard fanart as the same, but I can see how others might. I'm not going to ramble on about my opinions because Delphine pretty much covered what I would say.
Aaaaanyway, there's my two cents. As a point of assurance, I just want to say that past, present, and future opinions and views of mine are in no way meant to be taken offensively. I will try my hardest to present them respectfully and cordially, but in case someone receives it otherwise, I just want it to be said that it's not my intent. I don't mean to come off as rude or argumentative or negatively opinionated if it seems that way.
And now I've rambled. xD Rofl. Sorry.