If you have any more questions, please raise an issue regarding the same via email and I'll answer as honest and quickly as possible :)
Your name and your email address is stored along with your user information, if you signed in with Google, and of course, all the information you input in your resume is also stored in the database. You won't even get any marketing emails, feature updates, newsletters, notification emails, nothing.
Not having a centralized database cause a lot more problems than I could solve, mainly having a large chunk of the users of the app having an outdated schema as the app evolved. This was a problem I could not solve without having at least some control.
Also, a lot of users were having trouble printing their resumes on their browsers, so with the help of Cloud Functions from Firebase, you can now print your resumes remotely. None of the resumes are stored, and they are sent to you immediately after generation.
Not yet. But soon, maybe? One of the main motivations for me to shift to a centralized database approach was that I could one day build a mobile app as well that could let users jump from editing on their desktops to editing on their phones. It requires a lot of time, so I would not expect it any time soon, but it's definitely in the pipeline.