Those ambient textures on the first piece are really cool, I frankly feel jealous as hell that I didn't think to do that. Can I ask what methods you used to get those specific textures?
That aside, I liked the organs on the second track, but it felt like the frequency buildup in the low mids was really aggressive, just a quick reduction of a couple db in like the 80-140hz range (I did a quick and dirty check and that seemed to feel about right maybe?). Also you might get some decent results by carving out some space somewhere in the spectrum for the piano to come out more, and might get really nice results by putting a super subtle chorus on the organ, because rn it feels kind of mono. Take these suggestions with a huge grain of salt, bc I kind of mix to my own tastes and don't use organ super often, so these suggestions may or may not be something you want in your mix.
Also, whatever programming you did for those strings in the third piece sounds great, super killing it. The piano sounds great as well, the composition as a whole feels super emotive and I really like it.
I hope I didn't come off as negative at all, it just takes a lot of words to describe this mix stuff and way less to say that what you made sounds super beautiful and I really enjoyed it!