Amazing pieces!
I wouldn't classify part 1 as ambient tho, but as an OST orchestral piece just hits it perfectly.
I think the mix could use some work, but mostly around the low-mids, probably compression issues, not that its totally out there, but for the feel you went I beliee there might be a bit too much,
Composition is very very good, I always like storytelling aproaches.
Great job! Take care :3