The Node-Webkit export is a packaged app meaning everything you will need will be created for the three different platforms separately in a folder for you to decide how to distribute them.
The platforms will vary and have multiple files, such as the pak, and the exe.
If you like C2 will minify at the time of export which effectively obvusactes the code, not that the runtime would be easily deconstructed in the first place.
As to the speed, it will depend on the system, and on the game.
There are a few speed tests, some have C2 outperforming CC, and some vice versa, but CC usually only out performs on older systems.
That may seem a bit odd, but the reason is C2 runs on javascript, and older systems lack the power to cope with it.