On the idle, check all plastic and rubber air tubes from the mass airflow sensor to the throttle(s). Remember that things tend to crack on the bottom side first.
Does your model have the drive-by-wire throttle and multiple throttle valves, or does it have a single throttle and an idle air control valve? If you have a single throttle, you may need to open it up and clean the throttle valve and the idle air control valve. If you have drive by wire, that is beyond my expertise.
On the air pump. Bad news. Your check valve on the exhaust manifold has failed. That is why you hear exhaust pulses through the fan inlet. From the metalic churning sound I hear, you did not catch it soon enough and it has spun your fan backwards until it killed your fan as well. There is a place on eBay that rebuilds fans for $125 (half the cost of a new one), but the valve is not repairable.
To be sure that the valve has failed, pull the hose off the fan and blow through it. A good valve is normally closed. If you can blow into the exhaust manifold, the valve has failed.