build system for espruino

For the project I'm doing, I'm writing each layer as reusable modules. The layers are:

1. User interface (general purpose library for connecting buttons and such)
   
2. Timer and event emitter
   
3. State machine
   
4. Curve generation and output processing
   
5. Output transmission (I2C)
   
   

I need to know how these should best be assembled. I've read the modules page but I still have questions.

Does the web IDE perform all the minification? Do I stand to gain any improvements/optimizations by using uglify-js2?

Is CommonJS the most efficient approach for Espruino builds using multiple custom modules? If you look at the output generated by a CommonJS system like Browserify, you'll see that a lot of junk has to be wrapped around each module to recreate the CommonJS system within a concatenated file.

When it comes time to sell Espruino Picos flashed with my code, how do I setup the production process?