I tried to stay away from this topic...
Does a substance abuser lose the right to have their pain treated?
Yes, appropriately, which often times is not with narcotics.
Do we treat pain regardless of the cause or do we make a moral decision on who is worthy and why?
Yes, but you treat it appropriately. Narcotics are not the answer for everything.
As food for thought,
Anesthesia in surgery allows providers to inflict damage upon the body. (Under the intent that the damage inflicted is more beneficial than not inflicting)
Is it ok to inflict social/psych damage and not offer analgesia?
I'm not sure what you're getting at here. But I'll say yeah, but to me "analgesia" would be therapy, rehab, social services, etc, etc.
How many drug abusers will actually undergo reform and become productive members of society?
I don't know about Europe but here, very few, doesn't mean I should become thier dealer.
What drives the ones who do? Do you really think it is lack of access to thier substance?
No. I would say it's unique for each person, but ultimately has to be an internal drive.
If it is ok to palliate people with terminal illnesses, what makes it so reprehensible to palliate people with social/psychiatric affliction?
It's not reprehensible to "palliate" social/psych afflictions, but again, throwing narcotics at a known addict isn't the way to go about it.
Medicine shouldn't be practiced in a manner where "the customer is always right." Turns out people actually don't always know what's best for them.
Nice article illustrating that point from AIM this year: link to abstract
And nice commentary on the article on the blog KevinMD: link