Enable block

There is no available API to programmatically set a block. Like Drupal core does, we have to use db directly.

// we want to enable a block created by views 
db_update('block')
  ->fields(array(
    'status' => 1,
    'weight' => 3,
    'region' => 'sidebar_first',
  ))
  ->condition('module', 'views')
  ->condition('delta', 'blog_latests')
  ->condition('theme', 'bartik')
  ->execute();

Display errors - WSOD

The bootstrap override the values you could set to display error ad the reporting level. To be 100% sure everything is printed out when something fails in a blank screen (wsod), make index.php like this:

Properly render a field

Drupal offers a few (sometimes complicated...) solutions to output a field. Lets take an example with a date field.
To display the full rendered field: field_view_field()