about half a a humans normal room
This depends on many factors.
Roughly 300,000 square feet
yes.
That depends on how big it is.
None. If it is fully inflated it will be full of air so there would be no room for any water.
Air Conditioners and Refrigerators operate on the same principal - removing heat from one location and expelling it elseware. In this case, the fridge creates a much smaller "room" to be cooled, where as it would take much more energy to bring an entire room down to 1 or 2 degrees centigrade.
Enough room that you can see them
about 6 cm by 10cm
122434223GB it trew
That will take 27 sheets.
$30,000 would not take up much room at all. While it wouldn't fit in a wallet in $100 bills, it would fit in a small bag, or even a medium sized pocket. If put in a different form other than cash it could be even smaller. A rare gemstone could easily be worth $30,000 and weigh less than a gram.