In Adobe Acrobat Reader DC for Desktop, All my comments used to show abrevitions of my first last name to identify me, now it shows my full first and last name. Under the apps Preferences -> Categories -> Identify, it shows my first last name as my Login Name, Yet I used my Google acct which I deliberately changed my first last name for security reasons. I would like to not have my actual name displayed on the comments in case I want to publish or share the documents. It's a general security protocol, but I see no way to change this on the Adobe online acct or on the app itself. Help?
You can't change the login name. It's the name of your account on your machine (has nothing to do with Google).
You can change the default name used for the Author in your comments, though. Here's how you do it:
Go to Edit (or the Acrobat menu if you're on a Mac) - Preferences - Commenting and tick off the box next to "Always use Log-In Name for Author name". Now right-click a comment and select Properties. Go to the General tab and change the Author name. Make sure to also tick the box that says "Make Properties Default". Click OK, and any new comment you create (from that type) from now on will have your name as the Author by default.