The Bitcoin Uncensored interview with Arthur Breitman is interesting to watch: https://www.youtube.com/watch?v=gsY5wXj4Xm8
Everything else can be implemented by m-of-n multisig and off-chain oracles. This is something anyone about to invest in smart contract technology should think long and hard about.
Does he have a good explanation for this? Because I fail to see how something as simple as spending limits requires Turing completeness.