Kojima is still not sure about making the game third or first person. I would go with third person exteriors and first person for interiors, the camera could move into first person position as you open the door. Who's in with this?
I think always 1st person is the way to go for scary games like this. It gives that tighter more claustrophobic feel, as well as never quite knowing whats going on behind you. It also lets you play more with fov to make things seem closer or further than they really are, as well as make the rate of approach of things be more dramatic or unexpected.