Yes (which is why squids can sit on top of a galleon's balloon at height ceiling. I think. I don't actually know other than from playing the game.)
I'm pretty sure galleons can momentarily bypass the flight ceiling from posture + weight alone, just like how they're extremely resistant to the trade winds.
They can and with a coordinated crew and pilot it is one way to stop a squid blending a galleon, as long as the person shooting knows that they're going to have arcs for a few seconds, a well placed close range blast (hwacha or heavy carro) can save the galleon from the squid, it's only a few seconds window though.