Mewtwo, I edited the death boundaries for Mushroom Kingdom 64 in BrawlWall and I figured I'd let you know how I edited them, as it turned out pretty well. I'm not going to upload it, however, as I broke the teleportation system when I re-saved it using BrawlWall @_@ perhaps I should try finding these things in Brawlbox and editing them. Anyways:
I changed the top left death point (Dead0N) to X: -185, Y: 165. Bottom right (Dead1N) remained unchanged.
I changed the top left camera point (CamLimit0N) to X: -125, Y: 125. I changed the bottom right camera point (CamLimit1N) to X: 125, Y: -100.
So, the camera's horizontal boundaries were significantly shrunk down, and it works well. You can almost never see the DEAD ZONE graphic off to the side unless you pause it and rotate the camera--just like it was in Smash 64. You will probably see it sometimes still while playing widescreen, and you stretch the screen out very far horizontally and vertically. Does the stage feel a bit more cramped? Yes. But that's exactly how it was on 64
Also, it's not like you can't see the pipes or anything. It's literally very close to the camera in Smash 64.
Death boundaries remained horizontally because they were perfect. Vertical death boundary, however, was pulled waaaay down to be something much more sensible. Now it should behave as one would expect while playing. You shouldn't survive higher than you expect, and you shouldn't die earlier than you would normally think.
Just thought I'd throw that out there, though. I'm not even sure if BrawlBox uses the same coordinates for Cameras and Death boundaries