Which lifting, non surgical treatment has the lowest complication rates?

Each treatment that you mentioned has risks and benefits. It's important to meet with a board certified plastic surgeon for a consultation to discuss what your concerns are. She will evaluate you and recommend the tool that best addresses your concerns. Part of the conversation will be the risks to consider.

Much more information is needed, such as a full set of facial photographs and your age to make a determination about the most appropriate surgical or non-surgical procedure. The energy based devices really don't offer much improvement and PDO threads are very temporary.