Much of what I say would definitely be retreading old points. I see the points you're trying to make, and it all comes down to that I'm not getting the same read of Lavellan as you are. I don't see her a morally superior to others, she's just coming from a perspective that's weighed down by terrible hindsight. And Pride is young, and everytime or anyone else in Elvhenan even speaks casually of dwarves as less than equals it must send a chill through her, a reminder that in the end, Pride was so willing to burn her world.
You're right, Feynite decides how much Lavellan interaction has with others and what opportunities there are for people to question her. For much of the early story though, her interactions with others are limited by circumstance - first communication problems, and then the absurdity of her situation itself making it difficult to share with just anyone. Hence, she's somewhat isolated. Is that contrived so that she can spend time alone on her high horse? I don't think so. Most of her story she still can't even share with those she's friendly with, because it's nuts, and in Pride's case, too devastating. There's a recent chapter where she thinks about what it would mean to completely lay the truth on young Solas, and it's crushing. But in an even more recent chapter ... it all starts to come out. At this point, all I can say is that I hope you keep going with the story, and it gets better for you.
Going through bad stuff isn't an excuse for being a jerk, no. I've made that point with regards to Solas himself, and it irks me when I think I see people making excuses for him, even more so because I love the character myself ... and I certainly don't like feeling like I'm a cold insensitive whatever for daring to criticise a beloved character either. So if I've made you feel like that, I'm sorry. In the end, I find that I don't disagree with the broad principles of what you're saying - our readings of the character just differ too differently. I have tried to look closer at the text in light of what you've said about Lavellan, and yeah, I can see how some of the examples we've discused might be interpreted that way. But in the end, that's still not my sense of the character. We can probably both find lots of evidence to support our own views of her. We might have to leave it there. 