No need for flight shooting on-board a ship! It was sailing into battle, not sailing to land. This means everything on-board was for use at sea, otherwise it would have been excess weight - massively important to ships. That would suggest that the bows were used for precision, not mass volleys as (apparently) they were used during land campaigns during the middle ages.
It's a very recent thing to use a Warbow for distance, and doesn't reflect their use when they were needed for warfare. Just because they could range 250+ yards doesn't mean they were shot that way. Arrows were expensive, and archers were well trained. Doubtful that these weapons were used to shoot into the sky in the hope of hitting something when they came back down.
Depends what you mean by "simple" - in comparison to a composite bow yes, incredibly simple.
Simple to make - far from it. Getting any piece of wood to bend under the force of 180lbs without exploding is a difficult task, but to do it with so much finesse and care as is seen on these bows is a whole other ball game. When you see them in person, and see how the knots are handled, the tapers so perfect and consistent, and the tips so incredibly small at such high poundages, you could never describe them as simple, but they're about as simple in design as you could get.