I was born to a Jewish mother. Yesterday I ate a dish which contained shellfish, pork and milk products. Do you exhort me to present myself before a Beth Din? What will likely happen if I do?
Wouldn't that depend on whether you follow the religion or not? I think I read somewhere where you said you were an atheist.
Yes, I am an atheist. (Or whatever the correct term is for someone who tacitly renounces belief in a higher power.) However, I'd imagine that for orthodox Jews, if you're born a Jew you remain one, no matter what you do with your life. We'll see what Yitzl says anyway.
Yeah I heard the same thing. We know of a Jewish lady who entered Islam and her parents will always be telling her "Your still a Jew, you have Jewish blood" or something like that 
Anyway, do you call yourself a "Jew?"-I found it hard to believe someone can be Jewish and not believe in God, since I thought that had made up the foundations of the faith?
This is just me asking, I heard there's many like that but never understood it.
You should make a distinction between Jews and Judaism, in the same way that you make distinctions between Arabs and Muslims, even though there are large overlaps
Judaism is a religion, yes, to which a firm majority of jews subscribe to.
Jews are above all a nationality (not a race, as Hitler believed). This is how they are described in the bible ("Am Yisrael" - "the people of Israel"), this is how, as Combob has aptly demonstrated, you can have Atheist Jews (as opposed to Atheist Christians/Atheist Muslims, which are unheard of)
-"A Jew should never confuse his nationality with his citizenship" - Menachem Begin, PM of Israel