A: When you share a dashboard or report, the people you share it with can view it and interact with it, but can't edit it. They see the same data that you see in the dashboard and reports and get access to the entire underlying dataset unless row-level security (RLS) is applied to the underlying dataset.
B: Depending on the sensitivity of an organization's data, it is often necessary to disable the ability to export or print reports.
Reference:
https://docs.microsoft.com/en-us/power-bi/collaborate-share/service-share-dashboards