Bike mechs can seem knowledgeable while they really aren't. I've seen this happen. I've seen mechs declare absolute falsehoods with the unwavering confidence of a biblical king... so there's that.

And I'd like to point out that the BB7's don't require delicate handling any more than any other precision bike component. I personally think front derailers are more difficult than the BB7, since the cage line up needs to be perfect and it's really difficult to set by eye.
The BB7 adjustment isn't a secret and it's dead easy when you know how, just like any other bike tune up. Those things aren't secrets either but you do need to look them up yourself. Actually, with every part of bike maintenance, 'you just need to know how' so lotsa red flags in a bicycle.

The brake rub after wheel removal is not particular to the BB7 and can be completely avoided with consistent wheel attatchment routine.