A 10 MPH impact can cause some serious damage even though speed that low may seem pretty benign. Many times the damage is not visible to the naked and/or untrained eye.
I’ve been involved in the repair of quite a few curb strikes and my non-scientific estimate of the number of vehicles that had suspension damage after a curb strike would place the percentage at about 90%.
The lower control arm is the component most likely to become damaged although it can get much more serious than that; especially at speeds around 20-30 MPH.
It’s also possible, and quite likely, that a car can drive just fine in this condition. A preliminary check with a tape measure from some common datum points can reveal a problem. In less obvious ones it may require putting it on the alignment rack.
My feeling is that your car was seriously damaged goods from the wife’s curb strike and this is what led to the rapid tire wear problem over the next 2 months. The dealer states they hit a curb too but the most that would happen would be that they may have exacerbated any pre-existing damage.
As to test driving the car (off the rack) with known suspension flaws this may have been done to see if anything they did made any improvement. To me it’s actually pointless but I would probably have taken it out on a short hop just to see what it was like.
This is a pretty convoluted issue and I don’t have a definitive answer for you at this point. You might keep us informed and post any alignment specs back here for discussion.
(I had also referenced the strut towers in the event this was a pretty hard whack. They should be carefully examined for any small signs of cracked paint or undercoating. This often denotes a very serious problem that may require a body shop to repair.)