Sounds like you are taking all of the right steps. Is he going into shed possibly? That's my guess on his belly. Usually with scale rot you can see a few patches that are extra red/sore looking. I would keep a close eye on it though, it seems like the middle has some line patterns which could indicate the beginning of scale rot. As for his eye, I'm thinking that's just his eye color sine that is where the yellow pattern runs through his eye. All BPs have a slightly different color to their eye where that stripe runs on the face. If it's something new, I have no idea what would cause that.
And I'm with you about him not eating. It could be from the meds, it could be from breeding season. He's at a healthy weight so there's no sense in force feeding him just yet.