How do you ensure accuracy of your query
You can do this pretty easily using SUM and CASE:

SELECT 
    COUNT(*) as 'Total Rowcount',
    SUM(CASE WHEN LEFT(BARCODE, 1) = 0 THEN 1 ELSE 0 END) as 'Leading Zero Barcode',
    SUM(CASE WHEN LEFT(Foo, 1) = 'X' THEN 1 ELSE 0 END) as 'Leading X in Foo'
....


Then you get a number for the WHOLE table/query, and a breakdown of each category, all on the same line.  It'll be easy to see if you have a bad query since you'll get a low/high rowcount or something else.

This has the added advantage or processing more efficiently than a bunch of separate queries, since you just evaluate the whole table once.