Yes, there is a website that lists used hot water tanks. You can get a list of them at www.energystar.gov/index.cfm?c=tax_credits.tx_index
the hot water temperature will not reduce due to atmosphere temperature.
To prevent the heat dissipating.
There is no way short of cutting it off. Hot water tanks are not made to be opened.
Most home electrical hot water tanks will hold 40 gallons.
What ever your hot water tank is set at -- must likely not more than 120 degrees I set hot water tanks at about 110 degrees
As long as you have the same model.
All major home improvement stores will have information on hot water tanks. Some of these are Homedepot, Lowes,Menards and Ace Hardware. Information can also be found at websites of these stores.
Recycling centers pay for scrap metal by the pound. Therefore, how much you can get depends on the size of the tanks. There is not a very big market for used hot water tanks,for safety reasons. You may be better off trying to sell the tanks as scrap metal.
YES,YES,YES,YES,YES
Plumbing stores,Lowes, hardware stores.
a fiberglass insulation blanket that has a plastic jacket, they sell them specifically for hot water tanks