Levels that noone plays

- Self-explanatory?

Not having "Battle/CTF/Treasure MP level" checked in JCS

- The opposite of being explanatory at all?

Horizontal split screen mode instead of vertical

- Obviously any two people playing split screen will be sitting on left and right sides of the screen, not top and bottom sides of the screen. The person on the left should use left side and person on the right should use right side. Using top/bottom split screen is virtually pointless.