Reply to Question about a mixer

Hi there! Well, I've been looking to buy a 4-Channel Mixer lately and the one that surprised me was the Behringer NOX606 (I know, I know, Behringer uses to be shit). It has 4-EQs, two mics, FXs... There are a few questions I had about it:

1. How does the USB soundcard work? Can you run each channel of your software like Traktor into each channel on the NOX606 or you can only output the sound from the computer to one channel?
2. Can you hook an effects module? like the Kaoss pad 3 or the RMX1000
3. Is the 4-band EQ very different than the 3-band EQ? I've seen it in the Allen & Heath's ones and people say it's awesome, but in a Behringer Mixer? whatever.
4. If you had to chose between the Behringer NOX606 and the American Audio 14MXR, which one would you pick? I saw the American Audio for 250