The Chofetz Chaim (?? ???? ??? ????, ?????? ????? ??’ ?”?) writes if someone’s health is affected by smoking he will definitely be punished “???? ??? ?? ??? ????? ???, ??? ?????”.
Even though an addict has it harder he can still have free choice.
The question about the “addiction” makes sense. But even if someone has the addiction, engaging in the addictive behavior is still unacceptable. There would be an aveiroh for that. And this includes all addictions. ?????? ????.