Are there any fresh ideas enlisted in this definition? How would you have defined this idea? Are there ideas similar to it that you could choose to define?  Yes the idea that a yankee is kind has never occered to me.  I'm not sure how I would have defined this idea but it would have gone along with the idea of the baseball team.

There are allusions here: (1) to the musical Damn Yankees!, (2) to the Bible (the parable of the Good Samaritan), and (3) to a poem by Robert Frost. Do these allusions add anything to the essay or to your understanding of things? What if you didn't "get" the allusions?   If somebody were to able to understand these allusions, they are now able to look up all three and get a better understanding of what the writter means.

What techniques of development does the essay use in the process of definition? Do you think the writer dwelt too long on what a Yankee is not before moving on to what a Yankee is?   No I do not think the writer dwelt too long on what a Yankee is not because sometimes the best way to describe something, is to describe what it isn't.

Can you point to (write down) one sentence that functions as thesis statement in this essay?

That's what I think defines this dying breed of the American Yankee: an extraordinary sense of balance and reserve, a holding off — and yet, behind all that reserve, a reservoir of generosity and friendliness that can be nearly overwhelming.