A small dose of paranoia isn't unhealthy. I agree with your thoughts except about theater seating. I attempt to sit on the outside sections away from center. The rationale is this, if the building is on fire wait until all the PHRASECENSOREDPOSTERSHOULDKNOWBETTER. have stampeded and killed one another and then get up and walk out, you won't be caught in the onslaught. If the building collapses your chances are better near the bearing walls, where if you're lucky enough to get caught in a void you might survive relatively unharmed.
I also avoid the center of large crowded gatherings, prefering to stay on the perimeter to allow rapid egress if necessary.