Nxt doesn't have centralized points. It's PoS algorithm is different than all perrcoin clones, well according to CfB -- one of the main developer.
It is. I have looked through the code. The point in the Nxt forging algo is the determinism that outperforms any other PoS blockchain.
Peercoin uses another definition of stake:
- Nxt: Stake = NXT
- Peercoin: Stake = PPC x time