Hammer?? your doing it wrong, riding into gutters at full speed is more natural ;)
I figure you just need to get on and ride - tweak the wheels as needed.
Yep no different to old wheels, just keep your eye on spoke tension / rim truth and adjust as required.
My new Dura Ace 7850 C24's have not been touched in 10,000 from new but they would have been if they needed it!
Not sure who sold you that concept, but you don't have to break in new wheels. They work best when brand-spanking new (ask the pro teams).
Usually you hear a few pings from new wheels as the spokes settle. It is advisable to check spoke tension after a few hundred ks.
only if built badly...
Jeepers we're breaking in wheels these days....If you love your LBS and are looking for any excuse to give them money then go for it.
Breaking in tires though is another story all together. Particularly if racing as they get faster once they are scuffed up a bit.
never heard of this before
assuming they are better than K-mart quality just use them.
if they come out of true during the first ride go back to the bike shop and say they were not fit for purpose.
Any responsible bike shop will actually advise a buyer to bring the wheels / bike back for a retension after a few hundred ks. - - it is part of the after sales free service.
Bicycle Express have sold me bikes and extra wheels, but never suggested checking wheels.