Scott,
Regarding the issue of adjusting the volume of a particular drum part, I'm not an expert on this but I have a suggestion that might help. Last night I did a bit of experimenting with this, but I didn't have time to take it right through. I took a style and found that the drum parts were using Standard Kit 1. I then went into Standard Kit 1 and changed the level of a couple of notes (ie instruments). This got saved as the User Kit. What I didn't get time to do was to try to change the style to use the User Kit instead of Standard Kit 1. But if that works, will that give you a reasonable method of bulk changing an instrument's level? I could complete the 'experiment' if you like, or may be someone else can comment on the feasibilty of this proposed solution.
Mike