Store Specific Reporting Permissions.

Agree, this seems basic and if you have permissions set it should apply to reporting visibility as well

This needs to be not just for reporting but for the whole permission set.

We need to be able to restrict access by store as we use store sets to separate out physical locations 

Here to say that I agree, and need to add users to access just one store.

Needed: Store Access Permissions Per User

We definitely need a way to control access to different stores on a per-user basis. One specific instance where this greatly affects us in in regards to our test/development store, where we create and manipulate orders for testing purposes. We have seen instances where duplicate orders have been created: one order was in the live store where another version of it was in our test environment store, and customer service most likely created a return label (or performed some other normal expected operation) causing the duplicate to be created. It was not their fault: they performed their normal duties. This would have been avoided if customer service did not have access to the test store in the first place.