MPAStudent - re the buoys - pre-loading seems a great idea but removes versatility. Unless the buoys are configurable in the tubes (able to change depth of hydrophone, expiry life and, most importantly, radio channel), they will be of limited use. Reloads would also be needed in a standard MPA ASW mission - not unusual for a large amount of buoys to be used when tracking a quiet target. A big issue is the radio channel used to communicate with the buoys - there are a limited number and once a buoy is in the water using that channel, it is effectively blocked until the buoy dies.
Avtur covered most of the rest of it. Never forget the importance of visual lookouts - even if windows can't be opened, they should be domed to allow downwards view.