Sorry I've done some googling and I can't find any reference. I've heard it mentioned many times that satoshi thought mining was the inherent weakness of bitcoin. This quote seems likely because control of mining (which is what we see today with the large mining cartels) would lead to control of the network but I can't for the life of me find any reference to it...
Am I crazy?
I don't know. Maybe he admitted proof of work was somewhat wasteful somewhere (tell me if you find that) and you read it out of context or something. About "mining cartels" remember the hashing algorithm could be changed very easily o SHA3 or something else.
PoS has lots of potential for things like voting, just not for p2p consensus.
A hybrid system is less secure in the proportion in which it uses PoS instead of PoW and the savings in resources are arguable: miners today want to mine more by taking future PoS interest into account.
Pure PoS is just not secure due to the "nothing at stake" problem (basically you can vote 2 different chains as valid at the same time without losing anything).
NeST will be attacked one day.
I think the best option for counterparty would be a merged mined chain like namecoin, but certainly a PoS chain would be worse than its current parasitic form.
And again I do not mean to offend anyone, Peter Todd himself describes systems like Counterparty in these terms:
https://github.com/petertodd/decentralized-consensus-systems/blob/master/paper.tex#L252