This looked like a cool idea.

However, it's clearly insecure so I can't recommend it to anyone.

You say a login is required to run code but I can simply enable the Submit button and everything works? That's just extremely poor design.

The same is true for all of your stuff behind your "paywall." Simply editing the HTML in an editor renders your site usable.

You need to have validation on the server and the client. Simply providing client-side validation is not enough, especially for something that should be considered a teacher or tutorial.

neat idea and i like it, i am curious on what is your competitive advantage here - what would you say you do differently/better then let's say codeacademy ? And how much do you expect to charge people for this ?

I went to this site and left immediately after seeing a combination of bootstrap and really poor design. Regardless of how nice the backend may be, a project like this needs a designer to be successful.