Comments don't make it to the final exported c2runtime.js, neither do spaces and minimizing will also reduce the size of the file as much as possible.
As for editing functions out of the c2runtime.js, let's make the analogy with a car engine.
It may look as they are far more pieces than you need in the engine, but that's the way it is designed and works as a whole.
And if you don't use some plugins, they don't end up in the final js file anyway, so no worry on that point.