i think something bad needs to happen to Jun (lLike a car accident or something) to actually get kyou to pay attention to Jun. problem is Kyou is just being to adult like while Jun acts all kiddy like.
I usually see the characters like Ed as ukes and characters like Roy, Hughes and Scar as semes. I think Envy could be either way :) Also I guess Ed is actually quite tough, which could be why it is a little hard to see him as an uke^^
Totally see him as a uke, just because he is a uke - does not make him submissive, he is a tsundere uke, temper and all. Plus, his eyes are always so big (typical uke sign, and in this one he is smaller - another sign)
seems like a nice read