Need to Use a report and an alert to keep DB cleaned up

I hope that I can get a little creative in having SolarWinds help me keep the database cleaned up of nodes that have been down for 30 days or more. Here are my questions:

1. How do I use the Manage Reports tool to configure a report showing all devices that have been down continuously for 30 days or more?

2. For the alert, I want to trigger on any nodes that reach that 30 day threshold, with the trigger action being to change the value of a Yes/No custom property to Yes.

3. Last, I want another report that shows all nodes with a Yes value for that custom property.

I need help with the first two items. Thanks in advance.