Using Music Creator for live presentations

Hi, this is a continuation of a previous thread that completely changed subject.
 
I would like to create backtracks and play on top of them live. I got me Music Creator 6 three days ago, and started working on downloaded midi files. So far so good. I was adviced to create my own audio tracks for things other than drums and bass. Actually I play guitar and my fiancee plays bass and keyboards. So we will probably be recording audio tracks for these instruments, for anything we will not be playing live. For example, I will record my rythm guitar and play lead guitar... my fiancee will record the piano and play bass. I did some tests this morning and the results are promising.
 
I've seen some ads about Studio X1 and when two worlds colide, or something like that, saying it is appropriate for live presentations as well as recording. What would be the advantages of using Studio X1 for my live presentations?
 
Also, can I use the digital piano as a midi controler and fire up tracks in Music Creator using it?
 
I was also told to create audio backtracks and use them from a device other then the computer. And that I should not trust a computer that can have "stage freeze". Any other advice about using MC for my live presentations?
 
Thanks