Objectively valid only if needle exchanges are in fact "grease" (or "encouragement" or "cheese") - but your conscientious objection is another argument for leaving needle exchanges to private entities.
Experts in addiction would tell you, yes. I respect their wisdom enough to not ask for my government to do it.
Yes, I do believe in permission (meaning private) for people to go to hell, though not speaking well of those who thus indulge. That is the only thing that makes it meaningful for people to choose to go to heaven.