The scoring system is quite top-heavy and it has a hole in the knockout stage. I would have gone with something like 10 points each for correct round of 16 teams (160 points), quarter finalists (80 points), semifinalists (40), finalists (20) and World Cup winner (10), plus 5 points for the Third Place. What bothers me is that your scoring system has no points from quarter finals until final while the World Cup winner is assigned with lots of points. This makes the outcome of the contest very dependent on predicting the World Cup winner correctly while doing well in other categories doesn't matter all that much. My suggested system would award 50 points for the World Cup winner due to stacking of points throughout the knockout stage (5x10) while getting quarterfinalists and semifinalists right would also mean something.
How many points you want to hand out for each prediction is up to you, but quarter finals to participants in the final should be worth something. The rest of the rules is very coherent and comprehensive, but the scoring system isn't. I wouldn't assign increasing point rewards throughout the tournament, because keeping the same 10 points for each round already creates a stacking effect.