Awesome! Trying it out now. Are you getting a flickering effect with the textures when you zoom out a bit? I see it mainly on the characters and the front of the bottom platform.
As for the camera, I think it's a offset between the bounding boxes shown below:
Yellow is blast zone, which you probably already know. Normally it and the green box are aligned concentrically, as shown below:
I think the camera uses the blast zone line for the camera, so I'm not sure what the green is used for (some kind of stage object boundary?). If the green were for the camera and that was the problem, your camera would be aiming too high rather than too low. Or I suppose it actually IS for the camera, but it's not being taken into account for some reason.
And specifically, I notice that the aspect ratio of the inner green box is different than the blast zone. This misalignment might be causing the camera issue. I know that there are modifiers for the stage's size. Are these separated into width and height, and did you use it/those?
If we can find where those boundaries are defined, we might be able to modify it there (before the camera calculations check them). There is also another way to fix it, but it would be to use ASM to modify the camera's viewport per frame. This would work, but obviously be much more inefficient for the game than pinpointing the camera's own built-in variables.