Good questions. As you say, age is a calculated field and afaik won't be available.
Either you need to adjust how the DoB field is displayed which may be via js.
Only other option, for display purposes, would be to build (you guessed it) a Drupal view block and show that instead.
OK, so I had installed the Event Calendar extension from osseed, but had not installed the required JQuery Update module for Drupal. When I did that, and re-enabled the Event Calendar extension, now Event Calendar does not appear at the bottom of my CiviCRM Dashboard when adding a Dashlet based on a Drupal View.
I still have the whitespace problem when ...
Okay, I think I got it. First, start with Pradeep's answer and Laryn's in the comments.
There's a bug in the output text from Administer >> System Settings >> CMS Integration. It starts the block of text with $database_prefix = array( but it still needs the code as listed in the documentation (in an uncopyable screenshot): $databases['default']['default']['...
Try adding cms integration in your backdrop settings.php
CiviCRM >> Administer >> System Settings >> CMS Integration.
Step by step documentation : https://docs.civicrm.org/sysadmin/en/latest/integration/backdrop/views/
The answer is No, you do not, at least for Drupal 7. What I was missing was to first, add a new View, selecting CiviCRM Activities, not CiviCRM Contacts. I discovered clues starting on page 169 of The CiviCRM Cookbook by Tony Horrocks.