I had the same issue. Chased it for months (Link to build thread). I unplugged the power steering pump sensor wire and that fixed it. Well, it worked for me I should say.
You have some interesting things going on.
The High Idle Issue:
You said you clean the EGR, did you remove the intake manifold? If so, there are two intake gaskets that fit, but only one works. The one for the 3.2L engine is the same, but thinner material. This can cause it to fail. I went through of two of those in a month before I figured it out. The one for the 3.5 has a much thicker upper gasket.
You can check for intake gasket leaks by spraying carb cleaner around the intake and see if the engine revs.
Power Steering pump:
Does the pump have play? Or the steering? If it is the steering, that is just an adjustment screw. If it is the pump, sounds like it is time for a new one.
From everything you have said, it sounds very much like you have more than one issue at the same time. The high idle and low power are probably separate items to be repaired.
Good luck!
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VX Status: Running Great! Build is coming along nicely...