I am planning to create a website with around different 20 views/pages primary for mobile phones.
If I want to focus on a making the user experience very responsive (as
The short answer is yes.
Every second counts, people start abandoning your service if it takes anything longer than a second to load. So load only what you need.
Also, google has kindly provided this fantastic set of guidelines to help you get optimized for mobile.
I've had a fair amount of success using tools like RequireJS to load on the bits I need (and organization!). This can be paired with the framework of your choice like BackboneJS, AngularJS, EmberJS ... there's plenty of great one's out there.
The most interesting framework I've seen yet is Famo.us, they claim 40-60 fps on phones, PCs, and TVs. And their demos work flawlessly on mobile.