title screen stuff still doesn't work (probably never will)
While highlighting a tactic you can press select to increase its level by 1.
While highlighting a unit in the Set Members screen you can press select to increase its level by 1. Hold down square and hit select to increase its level by 10, and hold down triangle and hit select to increase its level by 100.
The menu in battles now allows you to go to the Design menu, so you can mess around with your rooms in the middle of battles.
Buttons on the second controller control the camera, too lazy to explain what does what... just hit them and figure it out for yourself :P
There are numbers on screen during attack sequences that show x/y cords and that kind of debugy stuff, as well as on the map during inspections, and a couple other places. They are more annoying than anything.
It looks like the debug mode is rather crippled, no interesting stuff left =\
Though it is possible that the code only turns on some of the debug stuff.