The only way it would "destroy the immune system" would be if the gold strands had HIV imbedded in them. As for any type of plastic surgery, there is the risk of infection and the immune system could react violently , especially if the recipient is allergic to gold. One possible future complication would be that the skin eventually pushes out the wire and for about 1.5-2 years before it comes out the skin would begin to fester and swell. It would not be a pretty site and surgery would definitely be needed. Also, 3 meters sounds like a ridiculous amount. That's around the length of the large intestine, imagine trying to fit that baby into your face.
Also, of course you could still wear jewelry, the gold wouldn't be visible, it's meant to stimulate the body into naturally reducing signs of aging. It's not like they're trying to insert gold into their wrinkles so that their facy becomes shinier.