Hello @Jeff Fazio - Thanks for reaching out.
I see that you are unable to delete the rule and trying to delete the RG itself, please see the below to see if there is any lock applied to it.
In order to delete the Resource group, use the below command:
> Remove-AzResourceGroup -Name ExampleResourceGroup
And use the below method to delete a resource.
> Remove-AzResource -ResourceGroupName ExampleResourceGroup
-ResourceName ExampleVM `
-ResourceType Microsoft.Compute/virtualMachines
To delete a resource group, you need access to the delete action for the Microsoft.Resources/subscriptions/resourceGroups resource. You also need delete for all resources in the resource group.
For a list of operations, see Azure resource provider operations. For a list of built-in roles, see Azure built-in roles.
If you have the required access, but the delete request fails, it may be because there's a lock on the resources or resource group. Even if you didn't manually lock a resource group, it may have been automatically locked by a related service. Or the deletion can fail if the resources are connected to resources in other resource groups that aren't being deleted. For example, you can't delete a virtual network with subnets that are still in use by a virtual machine.
Hope that helps.
If the above response helped, please feel free to "Accept as Answer" so it can be beneficial to the community.