What is the minimal set of privileges required to deploy artifacts to Nexus 3?

The general rule is nx-repository-admin privileges are for administering the repositories and their details; nx-repository-view privileges are for use of the repositories once set up. Assign the latter.

To tweak repository privileges of your Deployment user(s) you should use the nx-repository-view-*-*-* as the assigned privilege, instead of nx-repository-admin. So, remove all the privileges you addressed in your question, and replace the ‘Given’ field with nx-repository-view-*-*-*. Since the privilege is denoted with asterisks, your Deployment users can perform all the above actions (i.e. browse, read, edit, add, and delete).

See the screenshot for reference:

Configuring the nx-deploy Privilege for the Deployment Role

You can read more about Privileges in the Security chapter: https://help.sonatype.com/repomanager3/security/privileges

If you need minimal privileges to just deploy artifacts, nx-repository-view-*-*-edit is enough.

nx-repository-admin is used for administration and configuration

Repository Admin

These are privileges related to the administration and configuration of a specific repository

and edit is enough to modify repository content

edit

This action allows privileges to modify associated scripts, repository content, and repository administration.

BTW, you need nx-component-upload to upload components in web UI.

https://help.sonatype.com/repomanager3/user-interface/uploading-components

Successful deployment by maven 3 with Nexus 3.8.0 the following rights are required

nx-repository-view-*-*-edit
nx-repository-view-*-*-read