The first 2 things you mentioned, knowing your opponents, putting them on a range of hands when they act...and then the luck....the luck is the absolutely most important thing...if you have a run of bad luck that just won't end, it can destroy certain personalities....others are OK with it.
Luck is huge too. How many times have you been 80-90% on the turn & lost on the river? A lot I'm sure. Be really careful about going All-In, especially in a tourney.
I think a padded ass and a healthy back is the most important quality a poker player needs