The fuel tanks are not part of the hull per say they are bonded to the hull as part of the grid. http://caliberyacht.com/Features_Str...ain_Window.htm
as far as I know the only way to rupture a tank in a caliber or in any boat for that matter would be to shut off or plug the vents then fill the tank to deck level.
As far as too much fuel I don't think thats an isue they do make stabilizers with biocides that every one should be useing unless you motor so much you always have fresh fuel. I like the fact that I could if need be motor for 1400 miles. You can top off win its cheap and skip it win its expensive. and of course Its preferable to carry your fuel low in the hull other than lashed to your life lines in gerry cans.
The nav station is cramped but I would rather be wedged in to work win its rough than be trying to hang on and plot at the same time.
The bigist mistake they made on the boat was calling it a 40 its really a 39 and it actually started as a 38. I think all boats should be designated by water line length but that wouldn'nt be near as impressive. as haveing that 40 on the side
boats are all compromises if the shoe dont fit don't buy it. We love our boat it comes as close to fitting the bill for us that we could find. it is not perfect. The perfect boat is out in the nether world right inbetween the unicorn and the locheness monster.