For the record, I agree with many of your conclusions while not necessarily liking your method of argument. I'm a Finance PhD Student and my undergraduate education was in Economics from a top US university. The argument for re-distribution of wealth is that each additional dollar you get is less meaningful to you compared to the last. For example, imagine two people who both come across a $20 bill on the street simultaneously. One person is a millionaire, the other is homeless. It's pretty clear that $20 would make a bigger difference to the homeless person than the millionaire and would be more eager to get the $20 than the millionaire. So if a legislature wants to maximize happiness, a simple way to do it is to take dollars from the rich and give them to the poor. I have personal beliefs about how working to earn money - as opposed to being given money - affects happiness, but I haven't seen research on that topic. There's also the point that redistributing money costs money, so if the government takes a dollar from a rich person, less than a dollar makes it to the poor. My point is that economics supports a mixed policy bag, not extremely liberal, conservative, libertarian or any other ideology. I do however think that economists are more prone to be libertarian because they understand domino effects and aren't usually swayed by a few isolated negative outcomes.
RE: Do Socialists Even Have Real Arguments?