Two quickies
First, how do you change a units name? I know the trigger, but cant activate it
Second, an opinion needed. If I made a city, do you think it would look wrong if two identical buildings were next to each other?
First question: not a clue. In the editor, look for a button that says 'edit' or something when you have a certain toybox-unit selected. You might have to put it on the map first before you can edit it.
Second: It depends on the kind of city. With diverse architecture like the Naboo, it would probably seem cheap, but with generic stale buildings like Bespin or Coruscant, it wouldn't be that big a deal.
Number 2: I agree with leon, it all depeneds on the map.
Number 1, set the trigger to fire at something like 1-2 seconds. Then have the effect to change name. You could try to fire trigger at 0 seconds but i don't know if that would work or not.
If you need more detail just say so.