How to interact with dialog boxes using keyboard that appear not to allow keyboard interaction?
I did a little bit of searching and found this page on OSX accessibility.

They might be called "Utility Windows".


Control + F6 Moves focus to the first (or next) utility window 
Control + Shift + F6 Moves focus to the first (or  previous) utility window


Once inside, Tab and Shift tab can be used to navigate.

Interestingly, these shortcut keys worked with the following dialog boxes


Finder - View Options
TextEdit - Fonts


But did not work with these


TextEdit - Special Characters
OmniFocus - Inspector