I took Pravachol for two years. After first hearing that “no one else has reported this” I researched and found that it was a fairly common side effect. Then when there were reported deaths caused by Baychol (Bayer’s version of statin) I decided it wasn’t worth the risk. When I stopped taking the Pravachol, my cholesterol didn’t go up at all. I control my cholesterol levels with diet and excercise, which is what most people should do. Lower your excess body fat content, and your bad cholesterol will drop.
Lots of thin people have high LDL (though the incidence is not as high as with overweight people, as you suggest). My own high cholesterol problem started when I was still skin and bones.
It is extremely uncommon for LDL to be not at all responsive to statin therapy, as you experienced. Virtually unknown, and would have to indicate a very unusual metabolism, or possibly a defective statin product (has happened with counterfeits).
Non life threatening muscle and skeletal side effects are not uncommon, such as most myapathies and myalgias; serious ones do happen but rarely in any one clinician's experience. A doctor may never see a case of rhabdomyolysis.
Every patient should have a liver panel every year or so, more often at the beginning of therapy.