Sample Xml/SQL Code for #1.)
  <DataSets>
    <DataSet Name="ReportSubscriptions">
      <Query>
        <DataSourceName>ReportServerDB</DataSourceName>
        <CommandText>SELECT
    S.[SubscriptionID]
    ,C.Name + ' (' + S.[Description] + ')' AS DisplayName
FROM [dbo].[Subscriptions] S
INNER JOIN [dbo].[Catalog] C ON S.Report_OID = C.ItemID
ORDER BY DisplayName</CommandText>
        <rd:UseGenericDesigner>true</rd:UseGenericDesigner>
      </Query>
      <Fields>
        <Field Name="SubscriptionID">
          <DataField>SubscriptionID</DataField>
          <rd:TypeName>System.Guid</rd:TypeName>
        </Field>
        <Field Name="DisplayName">
          <DataField>DisplayName</DataField>
          <rd:TypeName>System.String</rd:TypeName>
        </Field>
      </Fields>
    </DataSet>
    <DataSet Name="LaunchSubscription">
      <Query>
        <DataSourceName>ReportServerDB</DataSourceName>
        <QueryParameters>
          <QueryParameter Name="@EventData">
            <Value>=Parameters!SubscriptionToLaunch.Value</Value>
          </QueryParameter>
        </QueryParameters>
        <CommandText>exec [dbo].[AddEvent] 'TimedSubscription', @EventData;
SELECT
	@EventData AS [SubscriptionID]</CommandText>
        <rd:UseGenericDesigner>true</rd:UseGenericDesigner>
      </Query>
      <Fields>
        <Field Name="SubscriptionID">
          <DataField>SubscriptionID</DataField>
          <rd:TypeName>System.String</rd:TypeName>
        </Field>
      </Fields>
    </DataSet>
    <DataSet Name="LaunchedSubscriptionDetails">
      <Query>
        <DataSourceName>ReportServerDB</DataSourceName>
        <QueryParameters>
          <QueryParameter Name="@LaunchedSubscription">
            <Value>=Parameters!LaunchedSubscription.Value</Value>
          </QueryParameter>
        </QueryParameters>
        <CommandText>SELECT
    S.[Description] AS [SubscriptionDescription]
    ,C.[Name] AS [ReportName]
    ,S.[DeliveryExtension]
FROM [dbo].[Subscriptions] S
INNER JOIN [dbo].[Catalog] C ON S.[Report_OID] = C.[ItemID]
WHERE
    S.[SubscriptionID] = @LaunchedSubscription</CommandText>
        <rd:UseGenericDesigner>true</rd:UseGenericDesigner>
      </Query>
      <Fields>
        <Field Name="SubscriptionDescription">
          <DataField>SubscriptionDescription</DataField>
          <rd:TypeName>System.String</rd:TypeName>
        </Field>
        <Field Name="ReportName">
          <DataField>ReportName</DataField>
          <rd:TypeName>System.String</rd:TypeName>
        </Field>
        <Field Name="DeliveryExtension">
          <DataField>DeliveryExtension</DataField>
          <rd:TypeName>System.String</rd:TypeName>
        </Field>
      </Fields>
    </DataSet>
  </DataSets>
  <ReportParameters>
    <ReportParameter Name="SubscriptionToLaunch">
      <DataType>String</DataType>
      <Prompt>Select Subscription To Launch</Prompt>
      <ValidValues>
        <DataSetReference>
          <DataSetName>ReportSubscriptions</DataSetName>
          <ValueField>SubscriptionID</ValueField>
          <LabelField>DisplayName</LabelField>
        </DataSetReference>
      </ValidValues>
    </ReportParameter>
    <ReportParameter Name="LaunchedSubscription">
      <DataType>String</DataType>
      <DefaultValue>
        <DataSetReference>
          <DataSetName>LaunchSubscription</DataSetName>
          <ValueField>SubscriptionID</ValueField>
        </DataSetReference>
      </DefaultValue>
      <Hidden>true</Hidden>
      <ValidValues>
        <DataSetReference>
          <DataSetName>LaunchSubscription</DataSetName>
          <ValueField>SubscriptionID</ValueField>
          <LabelField>SubscriptionID</LabelField>
        </DataSetReference>
      </ValidValues>
    </ReportParameter>
  </ReportParameters>

/// <summary>
  /// This method is called when this script task executes in the control flow.
  /// Before returning from this method, set the value of Dts.TaskResult to indicate success or failure.
  /// To open Help, press F1.
  /// </summary>
  public void Main()
  {
      try
      {
          Console.WriteLine("Working On " + Dts.Variables["User::AnotherParameter"].Value.ToString());
          ExportReport(Dts.Variables["User::SSRSWebService"].Value.ToString(),
                              Dts.Variables["User::SSRSReportPath"].Value.ToString(),
                              Dts.Variables["User::SomeParameter"].Value.ToString(),
                              Dts.Variables["User::AnotherParameter"].Value.ToString(),
                              Dts.Variables["User::OneMoreParameter"].Value.ToString(),
                              Dts.Variables["User::WouldYouBelieveAnotherParameter"].Value.ToString(),
                              Dts.Variables["User::TheLastParameterIPromise"].Value.ToString());

          Console.WriteLine("Finished  " + Dts.Variables["User::AnotherParameter"].Value.ToString());
          Dts.TaskResult = (int)ScriptResults.Success;
      }
      catch (Exception ex1)
      {

          // Try a second time
          try
          {
              Console.WriteLine(ex1.Message);
              Console.WriteLine("Retrying Attempt 2 of 3...");
              ExportReport(Dts.Variables["User::SSRSWebService"].Value.ToString(),
                                  Dts.Variables["User::SSRSReportPath"].Value.ToString(),
                                  Dts.Variables["User::SomeParameter"].Value.ToString(),
                                  Dts.Variables["User::AnotherParameter"].Value.ToString(),
                                  Dts.Variables["User::OneMoreParameter"].Value.ToString(),
                                  Dts.Variables["User::WouldYouBelieveAnotherParameter"].Value.ToString(),
                                  Dts.Variables["User::TheLastParameterIPromise"].Value.ToString());
              Dts.TaskResult = (int)ScriptResults.Success;
          }
          catch (Exception ex2)
          {
              // Try a third and final time, if we still fail then return failure.
              // These attempts are intended to deal with occasional glitches between PostGresSQL and our environment
              try
              {
                  Console.WriteLine(ex1.Message);
                  Console.WriteLine("Retrying ");
                  ExportReport(Dts.Variables["User::SSRSWebService"].Value.ToString(),
                                      Dts.Variables["User::SSRSReportPath"].Value.ToString(),
                                      Dts.Variables["User::SomeParameter"].Value.ToString(),
                                      Dts.Variables["User::AnotherParameter"].Value.ToString(),
                                      Dts.Variables["User::OneMoreParameter"].Value.ToString(),
                                      Dts.Variables["User::WouldYouBelieveAnotherParameter"].Value.ToString(),
                                      Dts.Variables["User::TheLastParameterIPromise"].Value.ToString());
                  Dts.TaskResult = (int)ScriptResults.Success;
              }
              catch (System.Exception ex3)
              {
                  Console.WriteLine(ex3.Message);
                  Dts.TaskResult = (int)ScriptResults.Failure;


                  try
                  {
                      //Try to Create a File warning the user about the problem
                      string noResults = "Unable to produce results for the requested report.  Please try again.";
                      byte[] bytesNoResults = new byte[noResults.Length * sizeof(char)];
                      System.Buffer.BlockCopy(noResults.ToCharArray(), 0, bytesNoResults, 0, bytesNoResults.Length);
                      var exportedFile = File.Create(Dts.Variables["User::FilePath"].Value.ToString().Replace(".","_WARNING_"), bytesNoResults.Length);
                      exportedFile.Write(bytesNoResults, 0, bytesNoResults.Length);
                      exportedFile.Flush();
                      exportedFile.Close();

                  }
                      catch(System.Exception ex4)
                  {
                      Console.WriteLine(ex4.Message);
                      Dts.TaskResult = (int)ScriptResults.Failure;
                  }


              }
          }
      }
  }

  private void ExportReport(string ssrsWebService
                                  , string ssrsReportPath
                                  , string SomeParameter
                                  , string AnotherParameter
                                  , string OneMoreParameter
                                  , string WouldYouBelieveAnotherParameter
                                  , string TheLastParameterIPromise
                                  , string reportFormat = "Excel")
  {

          // Report Server Settings
          var reportExecutionService = new ReportExecutionService();
          reportExecutionService.Credentials = System.Net.CredentialCache.DefaultCredentials;
          reportExecutionService.Url = ssrsWebService;
          var reportPath = ssrsReportPath;

          // Prepare Report Parameters
          var parameters = new ParameterValue[5];
          parameters[0] = new ParameterValue();
          parameters[0].Name = "NameOfSomeParameter";
          parameters[0].Value = SomeParameter;

          parameters[1] = new ParameterValue();
          parameters[1].Name = "NameOfAnotherParameter";
          parameters[1].Value = AnotherParameter;

          parameters[2] = new ParameterValue();
          parameters[2].Name = "OneMoreParameter";
          parameters[2].Value = OneMoreParameter;

          parameters[3] = new ParameterValue();
          parameters[3].Name = "WouldYouBelieveAnotherParameter";
          parameters[3].Value = WouldYouBelieveAnotherParameter;

          parameters[4] = new ParameterValue();
          parameters[4].Name = "TheLastParameterIPromise";
          parameters[4].Value = TheLastParameterIPromise;


          reportExecutionService.LoadReport(reportPath, null);
          reportExecutionService.SetExecutionParameters(parameters, "en-us");

          //Set Rendering Parameters
          var format = reportFormat;
          string encoding;
          string mimeType;
          string extension;
          Warning[] warnings = null;
          string[] streamIDs = null;
          reportExecutionService.Timeout = 3600000;
          byte[] result = reportExecutionService.Render(format, null, out extension, out mimeType, out encoding, out warnings, out streamIDs);

          //Create File
          var exportedFile = File.Create(Dts.Variables["User::FilePath"].Value.ToString(), result.Length);
          exportedFile.Write(result, 0, result.Length);
          exportedFile.Flush();
          exportedFile.Close();

          Dts.TaskResult = (int)ScriptResults.Success;

  }