Dave, the reason it is 2048 x 1080 is that it is for a festival and will ultimately be delivered on DCP @ 24fps (not 23.976.) “Scale to fill” seems to blow up the whole picture proportionally.
I think the problem might be on the side of the TVs as Tero suggested. As I said, it is perfect on my tv. I think one of the other tvs I tried it on is over sharpened, which is causing the white outlines/halo. The third tv that I tried only has composite video going from the player to the TV. It was by far the worse situation.
I am curious, however, if there is a filter in AE that will help the situation on TVs that are over sharpened without affecting the animation negatively. Or if I should go back to PS and blur all the edges.