Yes PIMS the HPV is usually harmless. (I'm not sure how this is hypocritical) Around 80% of people will contract it at some point in their life and the vast majority will not have any ill effects. A small minority may develop minor cell changes which may not need treatment and can disappear by themselves. Some people may develop more serious cell changes and these MAY develop into cancer if left untreated.
In your friend's case an earlier first smear could have meant an earlier second smear which may have caught the cell changes. It does definitely suggest that 3 yearly isn't enough if her cancer was able to develop in 2 years. Screening is the only way to detect cancer regardless of whether or not you have the vaccine. The vaccine is not 100% effective against ALL the types of hpv that can cause cancer ( 3 out of the 15 potentially cancer causing types out of over a hundred different types of hpv) if she had got vaccinated at 12 then there is no guarantee she would have been protected and no guarantee that she would have been still been protected in her early 20s so you can't say the vaccine would have saved her. We can't say screening would definitely have saved her either but earlier, more frequent screening would have given her a better chance of catching cell changes early.
You are acting like the vaccine is a risk free option that will prevent an extremely risky virus whereas actually, the risk of actually developing cervical cancer from hpv is very very small and every vaccine carries a risk. Gardisil, the one that protects against genital warts, has had serious side effects in around 1 in 25,000 doses(CDC) Serious is considered hospitalization, permanent disability, life-threatening illness, congenital anomaly or death. I think we use cevarix in the UK which doesn't protect against genital warts.
Re heart disease - a healthy diet and lifestyle would make more sense to prevent it.
I would argue that there is a greater risk of taking a relatively new vaccine with known, serious, potential side effects (and those are only what we know about now) for a virus that in the vast majority of cases will be harmless and in the small percentage of cases that can become potentially life threatening is treatable if caught early using existing screening methods that have been successfully preventing cancer and reducing the number of cases year on year. I think earlier and more frequent screening are needed regardless of whether or not people have been vaccinated because the vaccine offers no guarantees.