The following will remove all but "Listen Now" from Apple Music
Stop iTunes
defaults write ~/Library/Preferences/com.apple.Music.plist haveRadioState 0
sudo chflags schg ~<your_user_name>/Library/Preferences/com.apple.Music.plist
chflags uchg ~/Library/Preferences/com.apple.Music.plist
What you are doing:
The 'defaults write...'command will disable everything but 'Listen Now' under Apple Music. The 'sudo chflags schg....' line enables the system immutable flag for the file. The next 'chflags uchg...' line stops iTunes from modifying the file. By default, when iTunes starts it will reset haveRadioState to 1 and the Radio service will return. This could be a double edged sword in that this may deny iTunes the ability to update changes to preferences. I consider it a small price to pay for the benefit of removing those annoying Apple Music options and besides, once preferences are set, how often do you really change them?
More work to do. I hope to figure out how to completely remove Apple Music from iTunes. If I figure it out or find a solution I'll update.