What to do after deleting a million records
The problem of deleting large portions of a table is far from a trivial problem. The best approach, by far, is partitioning. A daily partition scheme with a sliding window is really a magic bullet for this problem, see How to Implement an Automatic Sliding Window in a Partitioned Table.

If you cannot afford partitioning (eg. non-enterprise license on site) then I would recommend clustering by schDateCreated. If you need primary key on the GUID+smallint then move it to non-clustered. Delete in batches (eg. TOP 10000), in a loop, to reduce pressure on the log. Consider updating stats after the operation.