will i have to set up each songs midi parts?

Yes, that is because with VSTs and Synths like ST we are moving out of the GM standard which was the orgins of all BIAB midi. BIAB is still fully GM compliant, but has now given us more flexiblity in sounds. With that flexibilty comes more responsiblilty on our part. BIAB does so many things, much of which certainly does not required sounds beyound those provided in a good GM synth (Coyote forte). Remember you can still use the GM for many of the instruments and just add ST for that extra sweet orchestral instrument. You decide if it is worth the extra effort.