It depends on what period you are talking about and how you define Greekness. The measure I choose is participation in the Olympic Games. Prior to the 4th Century only the royal family, the Argeads, which claimed descent from Heracles. Alexander I who reigned at the beginning of the 5th Century (498 - 454 B.C.) was allowed to participate in the games after claiming this ancestry. Though members of the Royal Family were allowed to participate 'commoners' were barred until over a century later.

Macedons did speak a version a Greek, though having not studied their language in depth I couldn't speak to how close it was to Koine or Attic Greek. Edit: The language is probably the most important indicator. Barbarians were called that because their language was unintelligible to the Greeks. It wasn't a judgement on their society or civilisation, so much so that the Persians, in certain fields more 'advanced' than the Greeks, were still called barbarians. Since the Macedons spoke a some what recognisable version of Greek they wouldn't be seen as barbarians.

I believe they were seen as something more than cousins to the Greeks. They were viewed as something outside proper 'Greekness' but not quite barbarians.

Source: Herodotus, Histories, 5.22, various classics classes.

I asked a similar question a week or so ago, if you're interested in the answers I got there.

And yea, like what fergusmck said, the Macedonians had a dialect, but wasn't as great as a factor as to why they were seen as barbarians. It was a more of a cultural difference between Macedon and the Greeks

I'm not sure what you're asking