No its completely not
Taking anything from someone else is considered stealing and is illegal, regardless of the fact that the stolen item is an illegal substance.
"Theft" is the unlawful taking of something that does not belong to you, regardless of its intrinsic value. Theft of even a shoelace is unlawful.
Yes it is illegal because it it vandalism.
It's illegal.
It is TRESPASSING.
Yes
no
Yes it is illegal to raid someones garbage.....
Yes Yes
It depends on where you are.
no but is is unormal and gross
not unless you get caught