Have you moved or renamed Photoshop CC installation folder? Did you install PS CC in the default location or removable drive? Please check "/Applications/Adobe Photoshop CC/Adobe Photoshop CC.app/Contents/Resources/AMT/application.xml" to see whether one or more path in it is incorrect.
For the slow loading issue, please update Extension Manager CC to the latest version (7.1.1) firstly. Then startup it. Click "Tools"->"Preferences" menu item in Extension Manager, check "Enable detailed logging" option. Restart Extension Manager. When it finishes loading or hangs, send all files in "/Users/<YourUserName>/Library/Application Support/Adobe/Extension Manager CC/Log" to exman.beijing@gmail.com.
Note: The Users Library user folder is hidden on starting with 10.7 or later
see http://helpx.adobe.com/x-productkb/global/access-hidden-user-library-files.html