If I may humbly suggest, I think that the game should be a bit more varied. For example, maybe the player has more character customisation and can choose which spiritual roots they have. If they choose a more talented person, maybe they will cultivate faster but fewer arts will be available for them. I also think that adding something other than just pills into the shop would be beneficial. The lifespan thing is also kinda annoying since you gotta manage everything. I think that if a player's lifespan is extended by like a decade or two every time they advance a stage (since it takes so long to advance to another stage), it will be a lot more enjoyable.
Almost everything you mentioned is already in my wish list of things to add in the future. Unfortunately, my free time is limited and I could only work on the game whenever I have the time. Not to mention, I'm still learning about coding and game dev.
But hopefully, this features would become reality in the future :)