Good grief, that's a complicated way to do it. As you had to write .NET code anyway, why not do the whole thing in a single script task, (or two if you wanted to use a separate SSIS mail task for error messages rather than write code to send an email)? Simply run the SQL commands within the .NET code. If anyone doesn't know how to do that, Google for examples; SqlCommand.ExecuteScalar to get the scheduling date and SqlCommand.ExecuteNonQuery to run sp_add_schedule.

Alternatively, you could probably do it all in one SQL procedure.

I did find the article useful though, as I didn't know about msdb.dbo.sp_add_schedule before.