you certainly have thought about this and covered your bases which makes you a safer gun owner right there.  i wouldn't consider a safe in a room necessarily accessible - the bad guy could be between it and you.  also a good shot can be hard to come by under the actual pressure and shock of finding yourself in those kind of  circumstances. there probably are advanced safety courses that teach strategy and keeping cool under pressure.  and staying out of high risk situations is tons safer in itself.  good luck to your family and congrats on being proactive - preparing and being responsible owners.