1) Generally with JMVC you are building single page applications (though you may have several pages for complex app with different layouts and share loaded code between)
2) with JMVC you will render all your views on client side using templates (EJS, Mustache)
3) on server with controller's actions should implement JSON API (RESTful or similar) - so your server responds with data, not html.You will represent this data to user using client logic (models, views, controls)