Check apache/php error logs, usually you get no messages or watchdog log if the error caused you Application/Drupal website to stop before reporting it. if there is any issue you should be able to view it from the error logs.

I believe that you need to have your ajax callback attached to the submit button not to the textfield, I suggest that you also check examples module (check ajax example module on how to do that drupal.org/project/examples). In your question you pointed to having this ajax attached to a content type, why do you need that? is on a field of this content type or is the whole content type submit should be submitted using ajax call?

@Clive the default region in .info D7 can be found drupal.org/node/171206#default-regions. and for more information about the defualt template check modules/system (core Drupal module) for the templates structure

Drupal 8 minimum requirement for PHP is 5.5.9 or higher. Then you should consider using a hosting with this minimum requirements.

The drush command is: Drush scr.There is a way to make Drush compatible by adding in the script file header #!/usr/bin/env drush and use $arg = drush_shift() to get the arguments as an array