Reply to SL3 Set-up Problems

Hi guys, forgive my ramblings to start please, I'm not much of a tech head and am having a few problems getting to grips with SL3.

I have installed SL3 with no problems at all (Acer Laptop). I connected everything up to my Cdj1000 mk3's and can get music to come through no problem. My problem is that while the track plays the deck rotates as it should but the waveform isn't moving at all? I have analysed all the music in the library but still nothong happens with the waveform?

Secondly, I havent calibrated it yet through the setup menu, how crucial is this?

Lastly, the laptop I am using is shared with my missus. Is there any way at all I can stop her music coming across from itunes into my serarto library?

Thanks in advance, Mark.