Drupal-7 - Lists and Custom Content Types
Organizing content with taxonomy (category) is a very powerful tool of Drupal.


  What isn't clear is when is a node not a node. For example, there are
  various support lists that I would like in my customisations, for
  example "salutation" (mr, mrs, miss, dr, revd etc) that should be user
  maintainable and stored in a database. It seems a bit overkill to
  create a separate content type and node just for this.


According to this, you can manage "salutation" with taxonomy . The"salutation" is a vocabulary and "mr, mrs, miss, dr, revd" are terms of the vocabulary. They will be stored in the taxonomy table and the path admin/structure/taxonomy/your_vocabulary will be user maintainable list page.

You can create a custom field ( term reference ) to your vocabulary ( "salutation" in this case ) for your content type.
They can be chosen from a list when user creates a node.

Same concept for your Event Type and Sub-Event Type.
The Taxonomy Manager module may help you.