Consider giving up on that install. Leave it running for now. Start a new install in a subdirectory. New DB. Start with fresh downloads of WP, WC and the TwentyFourteen theme. If it works, export your database from the current install and import it into the new one and add your theme and plugins one-by-one. Test each time to identify what if anything might be breaking the it. When its all working, point your url at your new install.
This time, use the latest version of your theme, have your customisations separately in a child theme, and keep caching off until development is finished.