Template Engine

It would be nice if we have the same template files for the front- & backend code. Maybe Handlebars do the trick, you can use it with javascript based MV* frameworks (Ember.js, Backbone.js..) and in PHP too.

The one thing I find useful with template engines in other frameworks and languages such as Laravel or Rails, is that you can open forms with routes or controller names instead of URL's. this allows you to change controllers, routes, or whatever config you want and not have to go back in and change the URL of the forms.

In CodeIgniter named routes are not supported, but you can do something similar with reverse routing: codefury.net/2010/09/easy-reverse-routing-with-codeigniter/
A few years back there was an idea to bundle the reverse route feature into CI, but it didnt happened: github.com/bcit-ci/CodeIgniter/issues/218

Alternatively, with the uri_string() method, you can get the current URI string so you don't have to set manually different target in every different controllers/actions. codeigniter.com/userguide3/libraries/uri.html?highlight=uri_string#CI_URI.uri_string
But it's only an option if you process the data in the same action what shows you the form.