CI 3.1 for Website Building Platform

Hi,

Preface: Please do not shoot down my idea by telling me how hard it is. I know

Question: Is CI 3.1 a good framework for developing a very simple site building tool where users can login, create a small website via a drag and drop interface, and publish it on a subdomain?

Also:

• What would you use for the Drag and Drop functionality, jQuery and AJAX?
  
• Would MySQL be a good option for this platform? I assume each user will need a separate DB
  

Thanks!