I am trying to store the emails and usernames of users who trigger an action type that modify or creates an object. I can do that for the id already, but am not sure how to get other properties?
Yes it is possible to store username and email of the current user. The easiest way to do that is to follow these steps:
This information will be stored in "Entered By" property. As they are multipass attributes, if you display such property in a table, the name of the user will appear.