The only thing that really bothered me was where both the Fleet and the Pirates were getting all their heavy ordinance from.

I can buy that they can salvage entire ships, I can buy that they can build their own small arms and ammo (though I wonder where they get the gunpowder), but both fleets were firing an awful lot of heavy armament. You can't exactly manufacture that kind of stuff safely onboard vessels in any kind of large scale production.

Especially the pirate fleet, which isn't remotely on the same scale of Gargantia nor did it have any kind of infrastructure and production ships like Gargantia has.