1
Sadly the arc with Rii-chan wasn't closed and her relationship to Kousaka. If she would had also been abused by her, Rii-chan and Jinno might have had a good chapter to come to a resolution.
2
I don't like the selfish ending, without a deeply meant or even forced apology for the disturbance that Kousaka caused in the live of this kid. After that while it might have strength Jinno character as an adult in the end, but non or less it was abuse.
3
As an "author" Kousaka had long enough time to get all viewpoints of her action together. Not to "excuse" her behaving in front of her "love-affair" with just lust and therefore it is all ok, because sure we are desire driven animals, is so far out. Yes we are, after all also social, and that point is in no way or shape addressed. For a love, and by the looks of it they got into the bed after this talk, they still treat each other like objects. This is inconsistent with the subjective love, they both share. For someone who wan'ts to bring meaning into the world with words (author), this behaving, seems very strange and out of any reflective worldview.