Is it possible to add fields to a Google Form which are visible only to specific users (based on their email ID)? Or allow only users whose email IDs fall in a set to fill the fields?
Google Forms doesn't include a feature to hide questions.
Google Forms could use page navigation to control wich questions will be available for the respondents but it's controlled by multiple choice questions, not by users ID.
Create an specific form for each set of users then send to each of them the corresponding form.
I have not tried this but I think probably Google Script might help you in this. Find this link to create a google forms programmatically. https://developers.google.com/apps-script/reference/forms/
This service allows scripts to create, access, and modify Google Forms.
With Google Script, you can access logged in users email id with :
By combining these two functionalities it might be possible to add questions as per users. I hope this might help you. I'll edit this post with proper code if I get the time.