It takes 6 months for Chaos to get GreenLighted, but it depends on how often you update and post “interesting news”.
(Greenlight system relie on Steam user’s vote for your game)
Regarding the burocracies, “4Realms SARL” is a french compagny, so we had to fill some forms like W-8BEN-E and SS4 document in order to proceed with USA customs.
Presenting our Game to the Steam community was great because it gives a preview of players’ feeling about your work. So you can adjust and shape your stuff according to some (usefull) comments.