Found a nice touch! The Find function remembers items even after Quitting the app. Ran several hours, with only on Quit and Restarting the app. Nice and stable, no crashes. Also now have a complete copy (including image files) in DropBox, duplicates of the .epub on the HD and complete backups of the css, html, ncx and opf files via BBEdit. (not to mention the TimeMachine hourlies!)
Thanks, again for the help and explanations.