Both greed and self-interest refer to motivation, that is, something existing before the act. According to you, however, we cannot tell the two apart until we see the results, that is after the act. That is certainly problematic, isn't it?
Actually, "greed" is in the same relationship to "self-interest" as "rich" with respect to "wealthy."
The latter terms are value-neutral, and the former are their disparaging equivalents. That's all.
Also, what evidence do you have to support your claim that Maddoff destroyed wealth? Fraud is not necessarily wealth-destroying: in every transaction the amount of wealth is constant. Think about that.
This is a fascinating and complex topic. You make some interesting points. Off the top of my head, let me respond to your challenge that fraud doesn’t necessarily destroy wealth.
Every time someone is a victim of fraud he is marginally less likely to participate in the market in the future. Fewer market transactions, less wealth. In a free market it is a transient effect. The first time someone mixes sand with his wheat to get a dishonest profit the market is disrupted. If every one starts doing it, the market would adjust, prices would drop and things would get back to normal (except the end user would be stuck with the expense of separating sand from the wheat). Fraud is worst in a regulated market. Say the price of a basket of wheat is fixed at 10 moneys. Now when people start mixing sand with wheat everyone gets poorer and stays poorer.