I am checking internally on this.

Server Call Usage report is not available for VRSs. You may check Occurrences to get an estimated server call count.

For the first issue, I would recommend reaching out to support team since it will need looking into your reports. For the second issue, why do you think values will persist in evars in Custom/Exit link calls?

Please check https://experienceleaguecommunities.adobe.com/t5/adobe-analytics-questions/annotation-in-analytics/td-p/373449. 

Creating a segment dropdown with all the available values in a dimension is not supported. A dimension can have 1000s of values, so creating a dropdown with all those values are not possible. 

Assuming you are trying  to debug a mobile app, you may use Project Griffon to connect, inspect and and debug.See https://aep-sdks.gitbook.io/docs/beta/project-griffon. 

Thanks for the details. I haven't come across such issue. This may be one-off, however, if you see it reoccurring with another Data Warehouse request, you may open a support ticket so that we can have a closer look.

Thanks. We have seem few similar issues in the past. Please open a support ticket so that we can further troubleshoot this.

As of now, Adobe Analytics does not have APIs to create/edit Workspace panels. Adobe Analytics 2.0 is a reporting API. 

This could be due to the report being scheduled to deliver hourly or daily. Can you check that?