Yea mate no worries, i got my Phone from American and i was worried just like you. It was cool though, i don't use the plug, i just connect to my computer, although if you have an American adapter then the plug can be used.
The maps function is worldwide, it's Google Maps so it's litteraly any place in the world, i was worried myself.
Don't worry, I did then when i got it i was like, i can't even notice any differences except time and weather apps, they are very easily set to your location.