Sophia, I think you did a great job on this segment! Your idea of having the dead Ingen send makes sense to me-- and you're right, it's a good way to do it-- though a bit confusing at this point in the story, especially since I think that the instant he died, he would stop feeling pain. It does seem to me that a simpler method would be to simply say, "Aroree couldn't know that it was only the stranger's acute pain that had pushed his mind past its usual boundaries, enabling him to send to her as he died."
Use it if you like! :)
I personally thought it quite appropriate that Littletrill had not been born yet-- in fact, I would have probably found fault with it if you had done otherwise. I agree that the story should follow the canon in every instance but this one change (Rayek's arrival among the Gilders). It makes it much more interesting if you don't change other things, because then the reader can see clearly the ripples that the one change you have made creates in the original plot.
I wouldn't worry too much about mischaracterizing those Gliders we know little about. You clearly understand the Gliders' way of life very well, and I found Aroree's reactions completely believable. I think that as long as they have the Glider mindset, you can do as you like with characterizations of Gliders who have not been fully characterized by the original authors.
Keep up the good work! I'm enjoying this immensely!
And I'm so glad Manga's injury was not a serious one!