I've just installed Facebook Lite on my Galaxy A3 with Lollipop and no root. It satisfies all my necessities except for one: the contacts sync, which is present in the full version of Facebook.
I've thought of not uninstalling the full version, but instead using greenify to prevent it from running in the background, so that I can open it sometimes and get contacts to sync, but I wish there was a better solution.
I could not find any specific app to sync contacts because of the restrictions of the new Facebook APIs (in order for them to work properly I should ask all my friends to manually grant permission).
How could I sync my Facebook contacts having just the Lite version of the app running in the background?