I have no experience with the SFX engine; there seems to be a trial version available for download
here though.
From what I can gather from a quick overview of the
page on the product it is capable of synthesising sounds from scratch (probably using frequency modulation) as well as altering an existing sound by running it through various filters.
Secondly, define "music creation engine". You will have to write the music yourself - there are numerous programs that allow you to do this, some with more bells and whistles than others - or you'll end up with very "unmusical" computer generated tunes most of the time. Music is rather complex and trying to automate generation of all but very simple things (or possibly a jazz making utility...

) usually just result in a random sounding audio mass.
"Why do programmers get Halloween and Christmas mixed up?" Because Oct(31) = Dec(25)