As far as selling miles or awards, I would not advise that, especially to a stranger, but on the idea of booking a round trip to use one way because it is cheaper, my thought is this:

The airlines were deregulated so that they could charge any prices they wanted, so why the heck should they be allowed to regulate whether or not people use the product. If a grocery store started selling half gallons of milk for more than full gallons, do I not have the right to buy a gallon and throw away the other half? The airlines have made this complex fare structure for the sole purpose of maximizing their profits, the consumers should have the right to make purchases to maximize their savings. To call it fraud is a double standard on their part.