Language pecularities

http://www.theguardian.com/media/mind-your-language/2014/oct/10/mind-your-language-american-english

The headline of the article I've read is "Divided by a commom language: why an American won't call you a "bloody arse ". It was written by Maraithe Thomas and peblished in the Guardian, 10 October 2014.
The main idea of the article is that though Americans and Britons have the same language, they talk in completely different ways. But still it shouldn't influence people too much, and they should be tolerable to each dialect and, probably, get something useful from both.

The author starts by retelling a dialogue with her friend, who asserted her that she had some changes in the way of speaking and said "You sound British". Further she gives us an explanation of these changes: she worked in the Guardian for three years with mostly British co-workers, and her roommate was British. She worked in New York, but it was "a plot of UK soil right in the middle of Manhattan".

The author goes on by saying that know her language is a hybrid of two languages: "about 75% American and 25% British". She says it's a real science to pick up new words from both languages, to adjust foreign speech.
The author also sais there are some British words Americans just can't say.
In conclusion it's said "It's a happy circumstance to have opportunity to learn the quirks of a different culture.

I found this article very interesting. I knew that American and British English are very different, but here I found a real experience, an outward glance.











I have some questions to readers:
1) Do you think the difference between these two languages is so much noticable?
2) What do you think about borrowing words from similar languages?
3) What do you think about the author's reaction to her friend's words "You sound British"? Was it really so offencive?