Yes, water is edible. In fact, you should be drinking 2L every day to keep your body healthy.
yes
Not if they are made from plastic, metal, or some other un-edible substance.
Its nutts
It's primarily water.
Leaves.
no
no it will kill you in 5 secounds
no
When the shells are closed. If open, tap them and if they close then they are safe to eat. If they do not close then they are not edible.
LOTUS and SEA LETTUCE
water and urine
Edible wafer paper is made from water, vegetable oil, and potato starch. When a starch is heated, individual starch granules absorb the liquid and swell. Edible wafter paper would not melt in hot water. It is more likely that it would absorb the water and become a mush, which might appear as if it melts.