SSRS Data Source enabled/disabled
It's stored in the Content column in the Catalog table as XML, and the Content column is in binary - so you'll need to decode it from binary and find the Enabled XML element.  For example, this will give you a list of the shared Data Sources with their enabled/disabled status:

;WITH XMLNAMESPACES  -- XML namespace def must be the first in with clause.
    (DEFAULT 'http://schemas.microsoft.com/sqlserver/reporting/2006/03/reportdatasource'
            ,'http://schemas.microsoft.com/SQLServer/reporting/reportdesigner'
     AS rd)
,SDS AS
    (SELECT SDS.name AS SharedDsName
           ,SDS.[Path]
           ,CONVERT(xml, CONVERT(varbinary(max), content)) AS DEF
     FROM dbo.[Catalog] AS SDS
     WHERE SDS.Type = 5)     -- 5 = Shared Datasource

SELECT CON.[Path]
      ,CON.SharedDsName
      ,CON.Enabled
FROM
    (SELECT SDS.[Path]
           ,SDS.SharedDsName
           ,DSN.value('Enabled[1]', 'bit') AS [Enabled]
     FROM SDS
          CROSS APPLY 
          SDS.DEF.nodes('/DataSourceDefinition') AS R(DSN)
     ) AS CON