Which setting allows the user to submit only once (online and offline) and edit the submission if needed?

@ivanradisson, regarding your first query:

You should be able to collect your data with the web browser without any issues.

Regarding your second query:

You can control this as outlined in the support article, but the issue is that if the user changes the browser and tries to make submissions, then the system will not control it. However, you could use the dynamic data attachment feature to control this, as outlined in this community post discussed previously:

Regarding your third query:

This is possible through the row-level permission settings. But the issue could be related to managing and sharing the project with a long list of users.