I do agree with you up to a point Jane, but individual differences have to be taken into account too.
For example, my father smoked 50 cigarettes a day from the age of 15 and died a "textbook" death from lung cancer at age 67. My great-aunt Edie (other side of the family so different genes) smoked 60+ per day all her adult life and lived to 91, dying of old age and vascular dementia. My mother too was a lifelong heavy smoker - though not at the same heroic level as her aunt - and died at 89, also of old age and vascular dementia.
However, one cannot infer from the above that smoking doesn't cause cancer. One might even infer that it contributed to the vascular dementia suffered by both my mother and her aunt, since smoking negatively affects the peripheral circulation.
It's also worth remarking that three of my father's four siblings, his father and his father's twin brother all died prematurely of different cancers - some only in their 40s. All were heavy smokers. My father's eldest brother - the only one to bear no physical resemblance to their father - also smoked like a chimney and died peacefully at around 90 with no sign of either cancer or dementia. This incidentally opens up yet another can of worms - the question of the generalised "oncogene", which most scientists still dismiss.
It's my understanding that hypertension isn't just one condition, but that there are several different causes. This means that not everyone's BP can be brought down by reducing salt. There is, however, a lot of evidence that it works in some cases, so it's always worth a try.
The cholesterol/st@tin question (I'm trying to avoid being taken down!) doesn't really have much to do with this argument. It's a different kettle of fish, being a peculiarly anglo-saxon scandal. I left the UK 40-odd years ago, having worked there as a nurse, and one of my former nursing colleagues tells me that UK doctors still routinely test only for total cholesterol, without breaking out HDL (the good guys) and LDL. Now, it's been known for a long time - well, outside of the English-speaking world anyway - that the important factor is the ratio of total cholesterol to HDL. The lower this is, the better - regardless of the actual figures. My total cholesterol is about 50% over the limit, and my LDL is high too, but my HDL even more so. If I lived in the UK or the US, my doctors would be pushing maximum doses of potentially harmful drugs. Since I live in continental Europe, it's my very satisfactory ratio of <3:1 that's taken into account, and my GP never suggests cholesterol medication.