It might contradict a route you are going with the edit, but could you make Obi Wan less of an asshole when they are being chained at the arena. Either that or you could keep him an asshole for Anakin's turn. The films work where Obi Wan is an asshole, going a different route might be welcomed.

I just feel like Obi Wan and Anakin aren't being much of friends. Ewan acts like Alec Guinness around everybody else, but when Anakin is in the room, he turns into his bitter grandmother. I keep expecting him to tell him to take out the trash.