Hi Rikki,
The Genos styles I have are the factory ones that have not been modified. I've tried some of the missing styles and they sound OK, the drums are playing but I can see in some of the styles that some tracks do need tweaking but not heavily from what I can see.
If you have a set of Genos styles that have been tampered with then I think they would sound worse, so ideally you'd want to use the ones taken straight from the Genos without modification.
As for the expansion packs, they just need converting as they won't play directly from download, you will need to load them into YEM first, then also upload your instrument key into YEM as well for it to convert the packs to use in your keyboard.