I see that the OP has already picked it up, but for anyone else in the same situation: I'll be a contrarian here and suggest that you don't want to leave the store until you know it's good to go. It's probably fine, but if it isn't then you'd want to know as soon as possible and have it dealt with.
In my opinion, a good store should be fine with a function test and field strip, or even test firing if they have the capacity. A less good store might not, but then I wouldn't worry about offending them. But always be polite in asking, of course. It would also be reasonable for you to ask them to demonstrate a function test and field strip - Just don't be surprised if the available staff don't know how to do either.
Weird stuff can happen anywhere between the assembly line at the factory and you taking it out the front door of the store. Accessories could be mismatched or missing. It could have the wrong number or type of magazines. It may even have been used and returned (it happens), or assembled/reassembled incorrectly. All of these are low probability, but not impossible. No, they probably can't get you replacement handgun, but I'd expect it to work properly. Some problems might be impossible for them to address, but they might mean you get a discount.