I do not use the term "yanks" in a derisive manner. More as a term of informal friendliness.
If you hit up yanks on Google you will see dozens of US based sites that use the term. And what about the New York Yankees?
No, I don't refer to the Russians as commies or the Mexicans as greasers ( is that what they are called? )
We do refer to the English as Poms and the New Zealanders as Kiwis and ourselves as Ozzies. Please be assured that if you call us Ozzies we will not in the slightest be offended.
Now all I have to do is find a croc. skin sheath for my machete.