Is there a way to press the Import button with a shortcut on the keyboard in the import dialog window? In a keyboard only image workflow, this is the only button that has to be pressed. All other dialogs can be handled from the keyboard. A simple Enter or "I" would be enough.
"press the Import button with a shortcut on the keyboard in the import dialog window?"
I believe you're asking how to click the Import button in the already-open Import window, not how to open the Import window?
In my LR 8.2.1 on Mac OS 10.14.3 and on Windows 10, hitting Return / Enter has the effect of clicking the Import button.
If that isn't happening for you, perhaps you could post a screen recording showing exactly which steps you're taking? (Screen recordings often call out small details that are otherwise ignored.) Also, please copy/paste the first ten lines of the menu command Help > System Info.