Regarding #3 on the post: You are right. I just revised it to:
“In that sutta, the Buddha explained to Susima that there are Arahants without any supernormal (iddhi) powers, because they were paññāvimutti Arahants, who did not cultivate arupavacara jhāna.”
However, if you read the rest of the sutta, the Buddha explains to bhikkhu Susima that pannavimutta Arahants get there by just seeing the anicca nature with wisdom.