Galleon is not the best pick when learning the ropes of this game. Medium guns have very poor turning arcs, and the galleon is not maneuverable enough to quickly reacquire a target should the enemy get on your very large blind sides. As a pilot you can compensate for this by taking phoenix claw, helium and chute vent. Be warned helium and chute vent are very dangerous items and you should practice with them in sandbox before taking them into a game.
With the exception of the merc on the rear your gun set up is fine. I currently mount a flare gun on the rear of my galleon as it helps with spotting ships in clouds and if an enemy gets on my rear blind spot I can put 20 stack of fire on his balloon. Other good guns for the back slot are the rocket carousel, flamethrower, and light flack. You will want a gun with a fast turn rate, wide angle of fire, and some disabling power. The purpose of the rear gun is not to kill the enemy but to annoy them enough to either back off or wander in front of your more dangerous sides.
If you are running manticore, hellhound, gat as your primary weapons I suggest your gunner take heavy and burst rounds, while your engines stick to heavy. Heavy works well on all three guns for making more shots hit at long range, but you will want one person with burst rounds to get the most damage out of the manticore at close range.
Also welcome to the game.
Ok, sounds like the Engineer will be busy!
But, other than that, couldn't the ramming bumpers help as well as the parachute in the back?
I guess I'm trying different strategies and seeing if they would work...
And, just a quick question, how would you say would be a good strategy to close the distance with enemies? I know snipers will be a pain for this ship, so I'm trying to think of a good way to close the distance.