Get a Dremel Tool! I've had mine for a couple years now and every single time I use it I think to myself "This thing is friggin awesome, how did I exist without one?"
I don't know that it'd help with your door sweep install, but I'm sure you could find some way to use it if you tried hard enough. And if you're like me, once you have it, you'll try.
Drill pilot holes for the screws.
Won't help any, but won't hurt either.
Could use it to trim the sweeper if too long, and sand down the sharp edges at either end.
Then polish the screws.
And the sweeper.
And the door knob.
Then the hinges.
and the bolt.
And the cat's claws.
The dogs teeth.
You get the picture.