This list is a handy basic tool to quickly find out how well was a Drupal webiste built. It is by no means comprehensive, as a full audit has to take into account particular websites specifics but it is a really good indicator of what you are up against.
If a websites fails on many of items on this list, this should raise a red flag. If you need more information about the items here, please contact us. We provide drupal development services and can answer your questions.