Is complementary and alternative medicine safe?

Usually. Since most aspects of complementary and alternative medicine have never been put to clinical trials, they are mostly ineffective. But the placebo effect is generally safe, so although you might be wasting your money, the only harm is the avoidance of getting an actual real diagnosis and proper treatment from a real doctor.
Depends. It can be, depending on the practitioner and the treatments / medicines. A word of caution.. use WITH good medical care, not instead of medical care. Your Dr will applaude your successes, but will want to ensure your safety. .
Proven vs unproven. By definition, "alternative" is different than modern western medicine. Generally any drug, herb, treatment, or procedure that stands up to rigorous scientific scrutiny is included in modern medicine. The problem is that many alternative practices, herbs etc do not stand up to scientific scrutiny and cannot be shown to work. They therefore remain "alternative". Be careful and watch your wallet.