Get some more experience under your belt before making suggestions on the fundamentals. If you play smart, the griefer can't touch you. A simple palisade takes 2900 strength to break by hand, and nobody has that atm. Sure, they will, but then the devs will just raise the bar further. Which, by the way, is a really stupid way to deal with it IMO, they should just make it completely impossible to break walls without a ram.
And your "simple" way of determining a good cause is not simple at all. What if I clearcut all the unclaimed trees around your village? What if I start building a wall around your claim, but just outside it, to wall you in for shits and giggles? What if I snatch the exchange basket as you're trading with someone on unclaimed land? What if I grief the shit out of your resource spot by overdigging (good luck covering the whole spot with a claim)?