Are the queries static or modified daily to run?
I would first check dates within the query. The second item would be the matching of input files.
The second item would be check the input to each query for total number of records.
I would then check to see if any new PTF’s were loaded and applied.
Start with the first query and see what the output results would be. Repeat until the last query.
Run the report with query and then do it again with SQL.
Why are you not using SQL to generate the report?