To be fair, I spent a decent amount of money on the game (not a whale, by any means, but still), so having a larger pool of 5*'s to use makes it easier.
I've only ever done the hardest difficulty, and probably average about 600 points per run.
I wouldn't worry, though, since the 50k seal is the most important objective to obtain, and at the rate at which you're going, you should easily reach it by the end of the event.
The 15 orbs and extra feathers are nice, but not a huge deal if they're missed.