Cosmetic surgery goes wrong in only a small percentage of cases. Sometimes cosmetic surgery goes wrong because people use terrible doctors. Every medical procedure can go wrong, and occasionally will. The question is weather it is worth it to get any kind of surgery that is completely unnecessary. It might not be worth the risk.
To say that cosmetic surgery is unsafe is to say that medical/correctional surgery is not safe. There are risk to all surgery and while cosmetic surgery is not a necessity, it is safe if preformed by an expert. I have had family impacted by cosmetic surgery to fix confidence after brain surgery. I wholeheartedly believe that it is safe, but it is important to remember there is risk with everything.
Surgery should be reserved for people who need reconstructive work after accidents or illnesses that affected them. They should not be done for people who want big lips and big butts. It is unnatural and not needed. Those surgeons are wasting their talkents just to make money off of vain people.
There are people out there who need cosmetic surgery for reasons beyond just wanting to look better. People who need such surgery for the benefit of their future health likely have better research and tools to help them. People who get lip injections and other purely cosmetic surgery are taking extra risks due to the lack of oversight, and the lack of need for the procedures.
Cosmetic surgery, like all surgery, is never 100% safe. There are risks involved and outcomes like Farrah's which can occur, unfortunately.
That is not to say that people should not get cosmetic surgery as something may go wrong. If people are aware of the risks (which they should be) and still wish to go through with the procedure, I see no problem. But to answer your question, no, cosmetic surgery is not 'safe' as such.