What are the benefits of statins in terms of prolonging life?
I suspect I won't be crunching as much numbers as you'd want me to, however here are some basic points:


Statins have shown a clear ability to improve the blood llipid profile.
Their use in primary/secondary prevention for cardiac events is justified by the belief that less blood lipid will leave less lipids to clog the arteries with. This is an old paradigm, and it is debated, even if we nowadays indeed give statins to all (potential) cardiac patients. There is evidence for a positive effect of those drugs, but it is not undisputable.
An enormous amount of money is made from statins, and the pharma pushes very hard for their use.
They do have undesirable effects, but those appear mostly early, so patients are usually well monitored for them and they mostly pose no real threat.


On the subject of women: women before menopause are protected from cardiac events by their hormone profile, and would therefore likely benefit very little from statins at that time. After menopause, women present the same cardiac risk as men do. I do not know if studies have shown a difference in outcome for statins in postmenopausal women. If you want to know more, I advise you to go searching for it on Pubmed

DISCLAIMER: The above does not represent professional medical advice, and is subject to debate.