Thank you so much for your careful playthrough and review. Actually, the first spirit vessel is roughly directly below the starting point—I'm not sure if you missed it. It's blue.
The probability of enemies dropping spirit orbs is a fixed 75%. Unfortunately, during your playthrough, that probability was full of drama for you. As for the jump and other control feel and details, thank you for your suggestions—I'll immediately find ways to fix them!
This is my first time doing map design, so my skills may be lacking... The looping tunnel near the three-spirit gate was actually intended to be a maze, but it seems it had the opposite effect. Thank you for this super long, super long review!! I'll keep working hard!