I've researched them both quite a bit, which (I'm assuming) is why I've gotten so many different answers to the same questions. They're both pretty hardy snakes, and I guess different people just get different setups that work for them and their snakes.
As for handling BPs, I've only handled young ones, loved how relaxed they are. King snakes (Colubrids in general really) I've handled quite a bit, of varying sizes, but only wild caught ones. They're native here (I've personally watched a common kingsnake fight a water moccasin slightly larger than it and win), I grab them any time I can, just to show my younger brother, who also loves snakes.
By "Tubs" you mean those giant rubbermaid things you use to store clothes so moths won't eat them, right? And locking lids? Like the clasps on the side?
Good point, our external body temperature is probably close to 90.