As for the first question : yes! That's exactly the point underneath this all, I'm glad it shines through somehow cause I wasn't to sure that it did. :D
For the second question : most of the times it will not kill you. Sam and Sara have some momentum so when you grab the polaroid and stop giving input you will go on for a tiny bit. Most of the time that's enough to stop the ghost from colliding with you. The ghosts also have a tiny 'free zone' where they visuallt collide with the player but won't kill you. This let's the player have 'close to death' encounters that lead to exciting moments. This also helps with the issue.
Standing still for too long leads to unpredictable ghosts however. Cause you never know when he will start moving again :)