Reset Safari from command line
From http://seanscus.blogspot.com/2012/08/completely-reset-safari.html

Open a terminal and enter the following commands to fully wipe out all of your old Safari settings:

mv ~/Library/Safari ~/Desktop/Safari-`date +%Y%m%d%H%M%S`; \
rm -Rf ~/Library/Caches/Apple\ -\ Safari\ -\ Safari\ Extensions\ Gallery; \
rm -Rf ~/Library/Caches/Metadata/Safari; \
rm -Rf ~/Library/Caches/com.apple.Safari; \
rm -Rf ~/Library/Caches/com.apple.WebKit.PluginProcess; \
rm -Rf ~/Library/Cookies/Cookies.binarycookies; \
rm -Rf ~/Library/Preferences/Apple\ -\ Safari\ -\ Safari\ Extensions\ Gallery; \
rm -Rf ~/Library/Preferences/com.apple.Safari.LSSharedFileList.plist; \
rm -Rf ~/Library/Preferences/com.apple.Safari.RSS.plist; \
rm -Rf ~/Library/Preferences/com.apple.Safari.plist; \
rm -Rf ~/Library/Preferences/com.apple.WebFoundation.plist; \
rm -Rf ~/Library/Preferences/com.apple.WebKit.PluginHost.plist; \
rm -Rf ~/Library/Preferences/com.apple.WebKit.PluginProcess.plist; \
rm -Rf ~/Library/PubSub/Database; \
rm -Rf ~/Library/Saved\ Application\ State/com.apple.Safari.savedState