re gun ranges
Based on our references http://www.amazon.com/Frigates-Napoleonic-Wars-Robert-Gardiner/dp/1591142830/ref=sr_1_1?ie=UTF8&qid=1375183249&sr=8-1&keywords=frigates+of+the+napoleonic+wars
there were no drastic differences between ranges of cannons at minimum angle. First grazes were between 200 to 600 yards and longest range was 3800 for a longbarreled 18lbs at maximum angle. (Royal Navy tests) all types of cannons were able to fire to 1000 yards (except carronades),
re stable gun platform
what about it? elaborate please
re speed
speed depends on wind, your angle to wind, we have not yet implemented speed changes according to the sea conditions