I unfortunately don't have the time to go back over everything you wrote (being at work and all
), but I wanted to say something : a person's motivations will normally never be completely logical or rational. The same will happen for fictional character (unless you're talking of a robot perhaps), so I don't think it's wrong for people to say his motivation are racist, or driven by grief (which are both emotionnal and/or irrational reason). I don't believe he is racist at his core, but from all information we've been given he certain appear grief-stricken at the consequences of his mistakes.
Although it's not impossible to come up with a character that is, always, completely rational, most people just aren't like that. Not even millenia-old mages
So, trying to find a completely logical reason for him to come up with his plan is, I think, the wrong way to look at it.
As for if it is a bad plan. Heck yes, it is. but I think he's too caught up in it to see it, at least for the moment.
The thing with Solas is part of him knows his plan is not a good plan and that he is wrong but it's such a wrought, complicated decision that, for reasons, he feels resigned to. Different if he doesnt like you, but if he's a friend or romanced, there's room in what he says and his body language that he's not 100% committed and would welcome the chance to be proven wrong again and/or stopped.
I think it was a friend Inquisitor who chooses to try and redeem him that he says that he welcomes the chance for you to prove him wrong again. IIRC - correct me if wrong, someone.
I don't consider him to be a villain either, mostly because slapping him with an "evil" label is too easy. Even at the end of Trespasser the information he gave to the Inquisitor was practically nothing.
"I'm Fen'harel, our god-kings were bastards, I created the veil, and now I'm removing it. Oh, and that won't go well for anyone currently living on the world. Sorry."
Solas, you vague SOB, get back here.
So yeah, there's definitely more to his plan.
I feel that we know so very little of his "plan", that making a valid negative judgement call is impossible, irrational, and illogical. We're seeing only the tip of the iceberg, so making a hasty generalization like this is, at best, presumptive, necessitating that we're making a lot of (perhaps unfounded) assumptions to validate this POV.
We know that he wishes to remove the veil and "bring back the Magic" to the world...Is that so bad? In my opinion, it's not. He wants to fix a broken world (which he feels he broke), that "he destroyed" , supposedly, by the heroic act of putting up the Veil to prevent the world from being destroyed by the Evanuris. Note that he doesn't take credit for "saving the world", which he did, but instead he can only see the negative, unintended collateral damage that his act of "saving the world" incurred.
He is so broken, so remorseful for these indirect consequences of his actions, that his name "Pride" becomes ironic. He has no pride left, after all this time, for anything he has done, even freeing the slaves and leading a noble rebellion that likely lasted hundreds, if not thousands of years. My opinion is that he seeks only to make amends, to compensate the world for what was lost, by removing the Veil, restoring the natural order of things, and restoring the world to what "life or living was like before the Veil". As shown by his other dialogue, he has no misconceptions about or, IMO, no intention to literally restore the Ancient Elves and/or Arlathan, and he realizes (in an overly-pessimistic manner) that there will be collateral damage.
It is my fondest hope, that in DA4 we'll be given the opportunity to soften the blow, and minimize the potential damage through education and reform, paving the way for change...Change is not necessarily a bad thing.