Ken,
You've certainly jumped into the deep end of the pool by focusing on 6/8! It is a time signature that is not native to BIAB.
BIAB is adapted to compound time signatures such as 6/8, 9/8, 12/8 by modifying the existing styles in 3/4 and 4/4. Also, even though the term "swing" is sometimes applied to a 6/8 style, in my experience, it is not relevant (it's a carry-over from the original base style in 3/4 or 4/4 that was used to create the 6/8 feel).
Below is a link to a thread on 6/8 in which I explain the above a little more fully. (It's my second post in the thread so you'll need to scroll down a bit.)
www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Number=406957Since the large majority of Realtracks are either 4/4 or 3/4, trying to use these to create 6/8 styled backings also requires some lateral thinking.
During the early stages of learning BIAB, I encourage you to work with 4/4 and 3/4 so that you develop a feel for the program's ability. It's amazing software! I constantly marvel at how typing in chords and pressing a button can create such a wonderful sound.
Hope this helps,
Noel