The 'dangerous' part about using EM for changes, is that you have no explicit transaction control. If you click the wrong button - oops - no other choice than to take the system offline and start digging for the latest good backup.. (and perhaps also start thinking of a good explanation to the PHB)
In QA you can do:
<do some SQL>
..if all went as expected, COMMIT
..if something funky happened, ROLLBACK
..after that, you're back to square on (boss and users hopefully unaware) and you can figure out what went wrong and how to fix it.