In short, there's no doubt that the Clef du Vin does something to the wine. The question is: do you really want to do to your wine what the Clef du Vin does & is it representative of what the wine will be down the road?
The concept of "aging" a wine is defined by the changes that occur in a particular bottle over long periods of time.
Ideal aging conditions are non-fluctuating ambient temperature around 52 degrees Fahrenheit, indirect or no sunlight, moderate humidity & zero vibration. All of those conditions being equal, what effects the aging of the wine is time & micro-oxygenation coming through the porous cork. The Clef du Vin introduces a different catalyst to this "aging" equation.
My guess is that the metallic component is a reactive metal that introduces ions into the wine. A similar analogy would be a copper mixing bowl adding ions to the albumin in egg whites making them fluffy when whipping them into a meringue. My assumption is that, by the addition of these charged particles into the wine, the volatile acids & esters that are dissolved in the solution are excited & thus vaporized. This gives the consumer the impression of the wine "aging" since the nose is immediately more open.
However, this is not true aging. We found that while there was a change in the nose, the palate wasn't improved at all &, if anything, gave a somewhat hard metallic taste. The wines that saw the most "aging" from the Clef du Vin had very pronounced metallic notes on the nose. Could this be observational bias? That is a very distinct possibility, but it seemed pretty apparent to us.
To answer the two questions I started with, mine is a solid "No". Introducing the possibility of ruining your wine by accidentally overusing the device is an unnecessary risk to take given the minimal benefits. Additionally, the benefits observed may not actually be representing the wine in a more optimum light, let alone how it will taste years in the future. I have never had a winemaker tell me "this wine would be showing a lot better if we had some ionizing metal around". Time in a decanter to breath, a better serving temperature, proper glassware or even a more optimum time in the moon cycle? Yes, I have had winemakers suggest all of these factors as things that would influence the way their wines taste, but not metal.
The only way to experience the way a wine will truly age is by patience, but for those of us who don't want to wait years, this is my advice: Buy a bottle of the wine in question & open it. Pour just a taste & sip on it over the course of 20 minutes or so. Then pour yourself another glass and sip on that for an hour or so, swirling all the while. What you taste over this period should represent the trajectory of the wine over the next 3 or so years. At this point there should still be 2/3 of a bottle left. Leave that for the next day. Taste once early the next day & pour a regular glass in the late afternoon early evening. This will represent the trajectory over the next 5-12 years. Leave 1/3 left in the bottle for the next day. Taste once in the morning. At this point the wine might have faded or start to fade. That will tell you that the max life span is about 15 years. If not, leave it again till the evening. If it tastes even better on this last tasting then you have a wine that can truly age for decades or longer. If the wine has faded at any point earlier than the last two tastings, then it's an early bloomer. The bulk of the wine might be passed it's prime if it's an early bloomer, but at least you have an accurate gauge on the wines age-ability. Then you can decide whether it's an investment you want to make accurately.