Hey acoustic art (Don), same exact problems and thoughts. Updated to Safari 12.0 today, it deleted old Adblock from extensions. Found "Adblock Plus For Safari" with release date of today (Sep 19, 2018) in App Store so I dowloaded and installed it.
1. Have no idea where the extension lives nor how to access it in order to customize.
2. Can't figure out how to add button to Safari toolbar (was super easy to do on old Adblock).
3. SCARY to read that Adblock Plus Icon can read my sensitive info (passwords, credit cards, browsing history, etc.) - big NO, NO.
Any clarification would be much appreciated.