Diki, not to be argumentative but the problem I see with your whole approach/scenario is not with the potential use and utilization of the arranger but with the average arranger user. I think the profile of the average arranger user is of a 70+ yr old male with modest technical skills and little desire to delve deeply into even the simplest of operating systems. Self training and study rarely goes beyond scanning the user manual to find where the power button is. Exploring the sonic possibilities of the instrument beyond what is factory pre-programmed, is rare to non-existant. "I just wanna' play" is the most common theme among this population. One thing and one thing only drives and excites most arranger players (and triggers the infamous 'GAS' attack) and that is 'FACTORY STYLES'. It is the quickest way to satisfy the one thing that Americans treasure most...INSTANT GRATIFICATION (I'm basing this mostly on my own profile ).

Sadly, I've reached a stage where 1.) all arranger styles sound the same to me. 2.) age has made me too impatient to learn anything technical in depth (I know about 5 functions on my $1200 cell phone) 3.) anything I learn and don't consistantly use, I forget in about a week (and am reluctant to re-learn it).

Forgive me if I sound negagive. It's just that I've come to favor naps over studying tech manuals. I still use my BK7m but only as a drum machine (the world's best) for rehearsing (I usually use live drum samples/tracks for recording if live drummer is not available). I have not used anything on it other than the original factory patterns.
I only play organ and Rhodes (SEVEN) these days but I get enough pleasure out of them to keep me involved in music and they're sufficient for the kind of music I enjoy playing the most. Yep, old age has taken it's toll.

chas