depending on how much water you use a couple days to a week.
2.00 t0 3.00 a gal. average
Yes
dont be careless
no, they can sit in the truck(but if you use a 5gal tank,some places make you pull the propane tank out while in use)
yes
buy a plastic coated female,it gets a little hot there
no
Kevin
PS- SteamBrite.com has one too I believe,you can look at one there