The funny looking button on the far left under File sends you to the mix where you can insert loads of different wavs. If you put them under each other and press play, they all play together. By using the individual track controllers or whatever to the left, you can control the volume and panning of that wav in the final mix. Have a play around with that until you find something you like and then use the Mix Down button to convert it to one whole wav file! BTW, I'm using V1.2 so yours could be different!
I'm not exactly sure what you mean by point 2, but if you mean listne to the backing track while you record vocals then yes you can! Open one window which has your backing track and then another to record. Press record on you record window and then press play on your track window and then sing to your hearts content! With using a mic, there shouldn't be any loopage in sound resulting in feedback (eg if your recording sound from a DVD by recording from the sound out socket and your line in socket is selected as being heard through your speakers, then your going to be recording whats coming out, but whats going out is also what your trying to record! Argh! Basically, causing feedback!) Whether you wear headphones to hear the backing track is up to you - if you don't you could get microphone leakage.
Basically mess around with all the buttons (thats what I did!) You'll soon get familiar with it!
Hope that helps!
"Freddie would have loved it" - Brian May