How to Prevent all contacts being added to WhatsApp WhatsApp pulls all contacts from my phone. How can I limit this behaviour? Making it choose only those which are necessary?
You can use XPrivacy so long as you are rooted to EASILY limit this behavior.

You simply select WhatsApp within XPrivacy and check off "Contacts" then it will disallow it(WhatsApp) to access your contacts.

If you are NOT rooted, I do not believe it is possible to stop.