Hi CS,
The easy and not technical way is to call the Mixing Console.
You can see there the basic effects for each part of the style.
Set the values to zero.
Unless you allready have done that.
Same with the midi songs.Use the Mixing Console.
The other way for styles is to call Style Creator,find the tab called "channel"and there is a choice: "5 remove event".
You must do this to each part/channel of the style for the events you want to delete.
For midi songs,go to song creator,go to "channel" and uncheck "effect","EQ","pan" etc
I don't know other more advanced procedures to remove effects on the keyboard.
Maybe some other guy will help you better.