I think you spot the real question. What are the tools that deal with data viz without forcing you to share the data?

As mentioned elsewhere in this thread, good free ones are: https://metabase.com and https://redash.io

Couldn't you create a few views with the necessary data and database role that could only see those and nothing else?

Probably, but giving someone access to the database is not such a great idea without a glue layer in between to control cache, rate limiting, etc.