Being Chinese - exclusive, inclusive, or birthright?

So, I did some thinking on what it meant being Chinese. The flipped it around and asked, how does one even qualify being Chinese in the first place? For that matter, an overseas-born one.

Here's a list of possibilities -

1.) By having an ancestral home in China, or home region / dialect group?
2.) A biological link or blood descent? Born of Chinese parents?
3.) By speaking the language?
4.) The practice of Chinese customs
5.) By displaying nationalistic/patriotic inclinations towards the mainland?

How much of all the above must one have before one qualifies?

Much to mull about.