To make smaller icons they either have to be smaller in both screens or they have to be done in composer. If Done in composer and smaller probably wont be interchangeable
With composer you can make them smaller on the homescreen and then the app screen would be larger...my crossbar themes started out as smaller icons but I increased them
Yes, I'm really interested in smaller icons as well. Previously I had a Curve 83XX and used the bPhone theme from rogersmj. This was a great theme because it was a regular zen theme with icons on the left and then the main application screen had 24 small icons.
Now, I find it strange that I upgrade to a BB with a better screen with higher resolution and the most icons I can get on the main screen is 18. I'm going to look into plazmic and see if I can make my own.