I'm wondering if there is an option for applying a rule to all fields of a certain type, similar to the way you can right click on a field and select "apply shared styles to every <field type>". Does this functionality exist? I know you can achieve this basic effect through creating a custom component, which is close but not quite what I'm looking for.
No, there's no way to have a single rule apply to all components of a certain type, but there are a couple of ways you could approach this situation. The best approach would probably be to make a custom component with your rule applied, by right clicking an instance where you have added the rule and selecting "Share as Custom Component", select the options to auto-publish the component and replace the source item with an instance of that component, and then use that component throughout your form instead of the original field type.