Hi there!
I have checked your attached file. Your demonstration is clear actually. We will have a script that runs using a time driven trigger, it will check if there are any emails in the sequences need to be sent. In the same time, it will check if you have any responses from the email addresses before sending them the next email in sequence. The email templates will be imported from the Google Docs listed in the mapping spreadsheet, and their text can be changed interactively, like adding the name of the recipient. We can add other features, like highlighting the paused sequences in a different color and more.
I will be happy to address any of your questions!
Sincerely,
Mohamed