Flash is no more native than HTML5. At this point it doesn't make sense to "place bets" on Flash at all, unless like the article author you've spent many years on Flash and are not interested in change.
Flash can create a 'native' PC or OS X app (OK, it consists of a standalone Flash player bundled with your flash App, but the practical upshot is the same unless some strange permutation of misconceptions has led you to expect 'bare metal' efficiency from something like Flash).
You can also have this type of 'native' using HTML5 and Nodejs. By using this component called node-webkit.
I just learned about this from Popcorn-time, they package a "native" app using this technique, and the application is all HTML+CSS+Javascript.
I've noticed several design suggestions in your code.