The reason you cant see whish gun is firing as haggerty says is because of lag. The ship is moving and what you see isnt what the other guy sees because its off by milliseconds. If you film another player taking off from a CV odds are very good that he will not take off from the ship, but off to one side or another floating above the water. Again, it is due to lag.
So while you thought a guy was firing from an aft gun, he could very well have been firing from a forward gun that wasnt damaged.
As for the sound issue it could very well be a conflict on your computer. I have heard of a couple of players having that issue, but only a couple through the years. If it was a game issue almost all 500 players would be having issues. Uninstalling your sound drivers and reinstalling them will change the address and maybe clear the conflict.
Yes the game is old, yes it has not had any major updates in some time, how ever it is well maintained and still is the top WWII combat game out there. The other games have bits and pieces of Aces High, but Aces High is the only one that has it all.