Brisker:
The list of poskim is staggering – that every cigarette is an issur d’oraysa. It is on tape from Rav Aharon Kotler ZT”L. The list in seforim on the subject is impressive. Sorry if you wish to minimize it. The comparison to gilui arayos is not frivolous. Suicide is a form of retzicha, and that places it within the parameters of the 3 aveiros chamuros.
DY: You bet I have an agenda. It is to eradicate aveiros. We just recited “Ki saavir memsheles zadon min ha’aretz”, that evil, aka yetzer horah, will be banished from this world. It is my agenda, and should be yours, too. So far, I have never twisted a halacha. I refer you to review the seforim with haskamos from virtaually all the recognized gedolim of today, with direct quotes from those of today and recent past. I will not bother with statements about tzaddikim from generations ago, when the dangers of smking were unknown. Yes, I have the agenda of those poskim (almost all) who recognize the issur of smoking.