If you give the option to "blow up" a city, you should at least have the option to develop the city too, for 2 reasons. The first is that I blow up a city today, then I go back to blow it up again tomorrow, I'd just be bombing rubble, wouldn't I? The other reason is the city owner should be allowed to develop some sort of a defence in order to be able to minimise damage.
And the city name changing, imagine you are in a plane, supposedly travelling to New York, and suddenly the name changes and the pilot comes on saying "We are now approaching Bill's BackYardAlleyVille. We hope you had a pleasant flight.", you'd be worried and confused, right?