For unlocking the Trophy Level, the 3 stars should not be any kind of trouble to unlock. Just hook the pairs that come to you and you'll have it easily. I had the 3 stars done by the end of the first sector.
A good strategy for Danger's Trophy Level is to immediately start off by spiraling and mashing the X button. Once you get to 10-15 pairs, you should then start playing on your own strategy. Of course, don't collide with anything or else you'll lose the round.