Not to mention gloves and boots wear out faster than most wetsuits do. A leaky glove in a 1 piece unit would render it useless, or you could cut it off and wind up where we started.
drylock gloved keep the water out. my mits are drylock and the only liquid in there is the sweat from my hands...
if your suit fills with water you arent going to sink.... water isn't any heavier than the other water around it.