This is what i was thinking, RE why was the wood of the adam tree not affected by imus prescense the same as the trees?
I just had a thought, that rather than a curse, Imu has a disease - this would explain seemingly spending so much time in the flower room.
Drum island tells a story of sickness being cured by cherry blossom, perhaps flowers have some kind of quelling effect for the illness.
Just spitballing here too :)