Ok, I red through most of the replies here now, instead of just replying to the OP. I've played almost every game that got labelled here as pk gankfest. I quit most of them not because of low population but for heavy pve grindfests.
Yeah you get pissed if you grind for good gear for hours and it gets stolen from you in 30 secs.
I think what's great about this game is there is no big gap power between new players and vets. No grind spots but exploration. So even demons need to go to the human planet and explore every corner. And beastman can freely kill them if they choose to. I think the beastman idea of not killing eachother will only put likeminded players together that will support eachother. Just like in WvW in gw2. If you see someone from an enemy faction, you just jump him.
I'm okay with debuffs in foreign planets that give you a disadvantage. I'm okay with adding elite npc beasts to the beastman planet to give the ppl who don't like pvp some extra protection.
But there is a flipside to this, and I'm loving it... no matter how much protection you add to the beastman planet. If you want to explore everything and gather all resources, you need to visit the demon planet ofc And because of the type of players that inhabit that planet, the beastman (and humans) will probably move there in huge numbers. And that will be lots of fun.
If this game gets develloped right, then the beastman planet will be the one with the highest population. So give it some extra love.
And my advice is that gear doesn't add that much extra (like gw2) and doesn't take a long time to aquire.