1. Gas mechanism has nothing to do with tamper-proofing transactions, thats what blockchain (or more correctly hashchain) is for.<p>2. There are Turing-complete languages which only allow loops with known number of iterations.<p>3. Check my presentation, If you want to understand Ethereum programming model:<p><a href="http:&#x2F;&#x2F;www.slideshare.net&#x2F;mobile&#x2F;nivertech&#x2F;ethereum-vm-and-dsls-for-smart-contracts" rel="nofollow">http:&#x2F;&#x2F;www.slideshare.net&#x2F;mobile&#x2F;nivertech&#x2F;ethereum-vm-and-d...</a><p>IMO Ethereum is just a first step in the right direction, the real solution will need to be much more scalable.