You don't need to join what you don't actually need. You also need to be careful writing your queries, not just the schema. The most common ones should be wrapped in views or functions to avoid the problem of everyone rolling their own later.

Performance generally isn't an issue for an arbitrary number of joins as long as your indices are set up correctly.

If you really do need a bulk read like that I think you want json columns, or to just go all in with a nosql database. Even then, the above regarding indexing is still true.