Need Help Configuring User Access in Power BI Report Server

1. If you have a fully qualified domain name in the url link the browser should not prompt end users to login. e.g. http://server.yourdomain.com/reports/browse. Also, I would recommend using a CNAME or alias for the server e.g. https://reports.yourdomain.com/reports/browse so then if you need to migrate to a different server all you need the infrastructure team to do is update the new server with the CNAME and all your links can stay the same. I'd also recommend using a wildcard certificate on the server.

2. I would use Active Directory security groups for folder access and a service account to run the data sources. The Active Directory groups can be setup to be managed by an administrator group. Then you can have your team added to the administrator group to then manage access to the folders.