it could live in a tank by its self
No a snail can't live in a snail.
Yes, there are types of snail that can live underwater.
Ounces in the US, grams elsewhere.
You could try but if it is expensive I would not
.7 depending where you live could be a gram elsewhere
in the garden
love and snuggels
Yes.
because snail has a very slow metabolic rate
Land snails live in ditches.
If the snail had wings and could fly like a pig then yes it could eat dragonflies.
Gary is a 3year old sea snail