How about someone who works in finance taking a stab at this:
First off, what this poster wants to do is not illegal. It is only money laundering if he is moving/hiding money for a criminal activity or with the intent to evade taxes--then it becomes conspiracy to commit tax fraud and actual tax evasion.
Any banking transaction of $10k or more in cash has to be reported to the IRS. Checks, wire transfers, etc. are not held to this as there is a paper trail. If this man were to refund you with a check there is no problem.
The actual problem is that every transfer he gives you over about $12k (I think that's the limit for a tax-exempt "gift") is subject to U.S. income tax. So every time you received money from him, you would have to pay taxes therefore making every transaction with him a losing one. Wouldn't take long to be in the 35% tax bracket, therefore making your 60k/year base salary worthless when it is taxed at 35% + state income tax + medicare tax + social security. Going to work would suck for you.
As for the AMEX angle: if you make 60k and are spending a lot, it's only a matter of time before you are subjected to a financial review. When you are unable to provide income tax returns or a bank account with a 6-month average monthly balance that justifies your spending, your account will most likely be VERY limited and/or closed. Your $30k/month spending ability is mainly theory. I am sure AMEX would cut you off if you even approached that and have you pay down some of the balance first.
In short, you sum up the problem with America. If you want a Centurion card, work hard and get the income to have that. Not everyone can be a high roller. Also, the pursuit of ridiculous status symbols like a Centurion Card is absurd. I'd rather have that cash in the bank or a nice sports car. A credit card in the wallet means nothing.
Remember, "Those who say, don't know. Those who know, don't say."