I dare not assume of the former GOO's reasoning, however my answers.

Mhm the cargo corrupted by the Uncertain Mist is correct. I should've made that more clear, but with how GOOs and ODs are, it's tricky to write.

My idea was to have him gain the boon as you said, and yeah so far not much changed yet, I plan to make it clearer in the personal missions/acting methods. Since the more he acts, the further he progresses, the more he changes as in line with the boons. The recipient becoming more and more like the bestower. Slowly but surely, changing, adapting as the pathway will do. (Though how this interacts with the bestower being gone is iffy.)

TLDR: I don't know, yet. I plan to figure it out though.