If you want to checkout a PoS system that's been around for longer, https://decred.org https://decred.org has a hybrid PoW / PoS system which seems to get aroun

If you want to checkout a PoS system that's been around for longer, https://decred.org https://decred.org has a hybrid PoW / PoS system which seems to get around a bunch of the issues listed here.