Concerning the redemption in death.
Well, we solamancers got a total of 4 chances to break up/end romance with him in game+trespasser, first after fade scene, second in the balcony, third one after temple of mythal. We are all warned by solas that it might not ended well, but we still insist

.
Our lavellan could just have gave up and move to the sweet cullen romance, or to ride the bull, but they didn't. In trespasser, even knowing his identity and insane plan, lavellan still have faith in Solas. In some way, I would say lavellan is just as stubborn as her boyfriend. (and TOUGH, I myself would just choose the broken heart dialogue in trespasser.)
So...from a writer's perspective, I don't know, is that possible for PW to ever have a thought that, maybe the solamancers deserve something warmer and happier after the long long struggle?
I don't really oppose redemption in death for Solas though, it is cliche, but I think PW would make it a
terribly beautiful and sad scene, just like the post-temple of mythal scene. However, why am I feeling that the more we talk about it, the more the people who are certain about it, the higher the possibility that Solas in DA4/5 would end up in an entirely opposite way? Bioware always love to surprise us