In order to have all characters available for NG runs you'd have to manage to complete Mission 7 (or 8?) without ever grabbing a weapon pickup then make sure to end a mission with exactly 10 grenades. This way no one's starting loadout includes anything extra. This is a complete pain in the ass to do so I figured I'd upload this in case anyone got interested in the game and happens to have uLaunchELF or some similar method to put these files onto the PS2MC. (direct download)