Also I am informed that if you are going to crash, it is dangerous to crash with a full bladder!
Indeed, good point, receiving a severe blow in the region with a full bladder can cause it to rupture, and that can turn an already non-nice crash (or barroom brawl) into something quite less nice even. One more reason for taking a leak before any flight (main reason for me is that I would just hate spoiling the fun of being airborne by dreaming of a toilet
).