JavaScript parameters - best practices for settings object/callback
I would prefer a setting object for each function you want to call instead of merging them together into one, because then it is clear who needs this parameters. Otherwise this information gets lost. And who knows what jquery will do with this options in future releases? Maybe something useful, maybe not.

I think it is okay to add functions to objects but you can it make a little nicer when you define these not directly in the options object, instead only referencing.

(function (window, document, $, undefined) {

    function successHandler 
    ...

    function myFunction(settings, sc, ec) {
    ...

      {
         success: successHandler
      }


Also I would prefer real names and no two character abbrevations. That makes the code more readable for you and the rest of the world.