One little problem with your Market Maker (or specialist) vs. PPT take. The market makers are independent business people out to make a profit. They do not work in the forex, bond and precious metal markets. They can move individual stocks but they can't move markets. To be profitable, sometimes they even have to move their stocks counter to the market.
What we have seen more recently is increased coordinated attempts to move the stock market in unison with forex, gold and the bond markets. There is only one party that can accomplish that. That is "The Working Group", or in our circles, known as the PPT.
As you stated, market makers have there own agenda. They could care less what direction the market is going. I agree that they will take advantage of market movement when ever possible but they only do that with the stocks that they make a market for. As a business, they are not organized to move markets. What I have seen recently is efforts to move the markets with no profit motive. The only ones that can possibly do that are those that control the printing presses.
Joe
Market Data 
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