I have studied the play of multiple people that end up high in the league (top 20) and found that most of them play extremely slow, they use their full 8 seconds of thinking, like that they avoid early busts and a loss of points (I know it's boring to just wait to act). The reason is that they are much more likely to get quite deep in the tournament, not extremely deep though, but enough to make points every time. They will be the shortstack of the table the majority of the time, but it is ok, because they are not playing for the win, just for the points, and because of the gradual scale of points, this seems to be the best way.
Also, do not bluff! It is still a freeroll where they are going to call you with any hand, so there is a big time to lose some points. Only play premium hands and be patient.