Thanks!!!!!!  About crashes, we are all plagued with the problem to one extent or another with B7.   One thing I have learned is "wait".  B7 doesn't like to be hurried.  Say you change a setting and the preview window starts to update... wait.  Wait for it to finish before making another change.  It is an aggravation but it has reduced the crashes for me.  It is not a complete cure but it helps.  Save often.

Also, a time saver in the wait game is if you are using soft shadow settings (that is a drag on the render engine big time), turn off the soft shadows as you continue to work on the scene.  Then when you are ready, turn it back on for your final test renders.

Again, thanks for the weeds.