"Yeah, yeah, yeah" said quickly, almost sotto voce: A New Yorkism. I have seen several instances of that particular speech mannerism in folks from the NY region, but pretty much never hear from native Midwesterners (US).
As to "You know" - a funny true story. I met a man from Vancouver, BC, when we were on a trip together, and he was complaining about how people caricatured Canadians by adding "eh" to the end of their sentences. "Well," said he," we don't always end a sentence in eh. But what I don't like is you Americans going around saying "you know" all the time. Its you know that, you know this. Well, sometimes you don't know, eh?" I swear its a trues tory, and I know he didn't have any awareness of that last "eh."