1 All 32 Characters
There's really an easier way to get all 32 characters: First, set the skill level to zero and complete the game with each character to activate all the mid-bosses. Next, set the skill level to 3 and using any mid-boss, complete the game once. Sho should then be playable. It should be fairly easy as most of your opponents are suckers for combos and projectile attacks. With the skill level still set at 3, play through with Sho, then followed by Eiji. Abel should appear after you complete the game with Eiji. Play as Abel on skill level 3 to get Veil, then complete the game with Veil to access Naru. Hit the 'SELECT' button to taunt, or as in the case of Vermillion and Nagisa, to reload if their clips are empty.

2 Camera Trick ( Maomao )
To be able to control the camera angle manually in this game, go to the KEY CONFIG screen, then place cursor on any of the LR buttons, and press L1, L2, R1 and R2 simultaneously. If done correctly, the controls for the LR buttons will be changed to camera view controls. You can now rotate the view freely, though the zoom function seems to be missing...