It is entirely possible and safe to play the game with a Facebook account linked to your save. You just have to be sensible about it. Don't exceed 600 stored energy, don't play during a Full Marks or House Pride event, and don't contact the support team. Those are the three most common ways to get banned. They're not guaranteed, but they come with an increased risk.
Also that post you quoted is from two weeks ago, what are you doing lmfao
Only if you go above 600 energy. As far as we're aware, you can abuse the other resource amounts as much as you like.