First person view:
While playing, press Square + Triangle + Start. Press Start to resume the game.
Fixed camera view:
While playing, press Circle + X + Start. Press Start to resume the game.
Return to default view:
While playing, press Start. Press Start to resume the game.
Change emblem backgrounds:
Highlight an emblem and enter the edit screen. Then, hold L1 + L2 + R1 + R2 and press Select.
Change pilot name:
At the garage, highlight "Change AC Name". Hold L2 + R2 + Right, then hold X and quickly hold Square.
You can start a mission that gives you money in advance but abort it before you take any damage. Then go use the money to upgrade your AC for that mission.
(supplied by: Jeremy Blincow)