If you find fault or something in the email/template you can always edit the changes, and these changes would be replaced in your current automation workflow.
That means, all those contacts who are in the queue will receive updated templates/emails edited by you, however, you cannot remove/edit a particular step after automation has started, you can only make changes in emails you want to send.
You can also open a LinkedIn message and hit apply edits and they will go live without stopping the automation.