This isn't credit card arbitrage. Let me describe one idea for how Credit Card Arbitrage could work. You take out a bunch of credit cards, as he describes. Preferably ones with zero interest for the first year, or 6 months. You extract as much cash from them as you can. You put a chunk of that cash in the bank to make minimum payments from, and then you put that cash into an asset that will return more over the next…
You are talking about using interest free loans from credit cards in order to make a leveraged bet on the price of gold; that is not arbitrage.
If gold decreases in price - and its close to record highs, however you want to intrepret that - you are taking a huge risk.