This would be my cartone: http://www.youtube.com/watch?v=CIpof-p7h8Q

This would only be issue if the rest of the game would be like a FPS-game. Here the enemies are relatively slow and don't have guns to shoot at you. Had you fps-controls, the game would be too easy and less intense, unless the enemies had guns as well, in which case it would hardly be a Resident Evil -game.

being able to play videos has nothing to do with gaming and DS doesn't need memorysticks, since data can stored directly to the game-cards.