When etherdelta deploys - they call a script of mine that calculates the md5 of their files in github and creates automatically a new version in Chrome Web Store.
I use my plugin whenever I visit etherdelta so I can be sure that their deployed version matches the one on github.com
Open orders are actually transactions that have been made to the smart contract. It is possible to monitor the smart contract and get informed on all the open orders.
I just updated EtherDelta Guard to version 1.1.149 that switches from md5 to sha256 which is secure.
This is why I love HN, people are really helpful and get straight to the point without any fuss.