As soon as you have a wrapper that all access goes through, which prevents you from accidentally dealing with all of the data at once, then using that wrapper solves the "delete world" issue.

As for DBAs being better equipped to deal with data than development, I agree. Which is why I question making DBAs even more critical path on interactive development than they need to be. Pushing responsibility for more and more features and complex requirements makes them do a job they aren't supposed to be doing, and puts up roadblocks for developers.

Cheers,
Ben