I had a go at implementing your scrollbar with varying levels of success. Here's where I got up to:
NOTE: These scripts are only my work in progress attempts to get a scrolling UI working, so if you want to use the script you should download A_Muster_Batch_v1_1.
The first thing I tried was to create a panel that could be scrolled by using the scrollbar's onChange to alter the upper bounds of the scrolling panel. I thought that if I created a static 'masking' panel, I could move a larger 'scrolling' panel around inside it, but unfortunately the scrolling panel redraws over everything in the window. This method would work ok, but it's pretty ugly.
Make sure you have over 20 RQ items before trying these next two versions.
In this one I tried sticking with 20 rows of info, but getting the scrollbar onChange to redraw the text fields and checkboxes to make it appear to scroll. The redrawing works fine, but changing the text fields and checkboxes doesn't. The problem is with the onChange definitions and how the correct looped 'j' variable isn't being passed to the function. For testing purposes, I've turned off all the onChange's except for the checkboxes.
Because of the problems with the last version, in this one I've abandoned the looped onChange definitions and have simply coded in all 20 individually. You should find that all the render checkboxes update correctly, so in theory this version will work if you go through and define each onChange twenty times.
BTW: Due to the same issues with the Render & Shutdown script, I'm guessing this probably still doesn't work on a Mac.
Hope this is of some help.