There are some websites comparing the JLA to the greek gods. Was that DC's intention to create all their characters after greek gods, or is that just some people's comparision? I know Jay Garrick's creation was influenced by Mercury, not sure about the others though.

JL in generally is modelled off of the Greek pantheon and archetypes

Not the JLA'a individual characters specifically (the 7 everyone associates with the JLA). Some characters in DC, like in Marvel burrow from various mythologies though. There have been Justice League writers however like Morrison (who famously) took the league and purposely played up the similarities to Grecian mythology. IIRC his table was:

Superman-Zeus

Wonder Woman-Hera

Green Lantern-Apollo

Aquaman-Poseidon

Steel-Haphestus

Flash-Hermes

Batman-Hades

Morrison's are.

They were probably influenced by the old western, "The Magnificent Seven".

@sovereign91001: why is Batman Hades? Everyone hates Hades