I'm a south african. Got a job in Cyprus / Greece can I obtain a EU passport or can I work there on a Visa and work permit

If you have a work permit you can work there, but its country specific. Passports are not given out so easily.

I am 18 year old south african born citizen. . my maternal grandfather was born in hungary. Am I entitled to hungarian passport?

I am 18 year old south african born citizen. .my maternal grandfather was born in hungary. Am i entitled to hungarian passport?

You should have started a new thread - in immigration law.

I wouldn't think you qualify for a Hungarian passport. But to be sure contact the Hungarian authorities.