I understand what you were saying lunatic. But there wouldn't be a rank thing involved with the fire control towers. Just like all other manned guns, first come, first served. Only one part of the fire control tower wish applies to the 5" guns on the DD's and CA. The auto 5" guns on the CV wouldn't be affected as, as far as I'm aware, CV's don't have a fire control tower. You won't have to man the guns all day or anything of the sort. If no one is there, auto puffy will do it's thing. And unless 6 (guessing the CA has 2 fire control towers for the 5" guns) people want to take control of all 5" control towers on the DD's and CA to prevent auto puff from those ships, well, poo. It will be no different than if someone of high rank hiding the cv in that regard. Only to find out who they are, you'd have to up a plane or PT and get a few screenies of it happening often and report them. Not sure if anything would come of it, I would guess it would warrant action. Hiding the CV is one thing. It's a valid tactic, but a crappy one. Jumping in guns for the sole purpose of allowing the enemy to sink the fleet is another.
Blinder, if I'm in the fire control tower of a DD, I would have all 5" guns under my control. They would, as mentioned earlier, be locked in HE mode. This wouldn't stop someone from jumping into one of the 2 manned turrets and shoot at air targets. If both manned turrets are occupied by players, I could take/would still have control of the 3 remaining turrets from the fire control tower, and can continue to shell with them.
As mentioned before in regards to the 8" fire control tower on the CA, I can use all 3 at the same time from there. However, I will ALWAYS have 1 gun under my control. So if two other players jump into the 8" guns, the gun not chosen by those 2 will remain under my control and I would still be in the fire control tower and able to use it from there, or switch to the gun itself.