About Qifrey and his potential medical issues - especially in the future.
Not to get personal, but I have been to the Doctor for some IssuesTM, and he ran some labs and basically said that my body runs on "fight or flight" mode all the time and that that's why I don't heal properly.
(For context, I use a cane on and off and some parts of my body will just. Stop working sometimes. Pain in joints, room spinning, all that good stuff.) From what we can tell, it's a stress disorder of some kind. My body's cortisol is so high all the time that it doesn't know when I am and am not being attacked, so I don't rest well and can't heal.
Qifrey has been in a similar, self-induced state for around 20 years for survival purposes. I know everyone loves to think about the happy (if possibly angsty) ending where he gets rid of the tree and lives with his little family in his atelier forever HOWEVER.
The medical issues that long-term stress causes are genuine and can be quite severe. Qifrey isn't going to have a smooth time, even physically. Issues he could face in the future, even when he's in a safe situation include deep breath:
Anxiety, depression, issues with memory and focus, trouble sleeping, (more) headaches, muscle pain, digestive issues, sexual issues, heart issues, shortness of breath, stroke, vomiting, appetite changes, wild mood swings, and severe illness from the crash if he ever does truly relax.
Basically, what I'm saying is that even if the tree is removed and Qifrey can start to live a normal, happy life, he's going to go THROUGH it medically.