I find the trick with any die is to figure out the shims. The dies and machines are all different so you need to see what works with yours.
The crease pad is a worthwhile investment. It will prevent cuts in the scorelines.
If you have a spot on your die that consistantly doesn't cut in one spot, put a small piece of masking tape on the back of the die in that area instead of shimming the whole thing.
For the pillow box, my sides bow out too if I don't crease the folds with a bone folder to crisp them up (especially the two ends you're having trouble with).
For 3D projects and sticky strip, Try to burnish the card stock with the bottom of your bone folder to really get it to stick.
Patty Bennet did a great tutorial for resizing your scallop envie die to fit a gift card. Here's the link
http://pattystamps.com/pattys_stampi...gift-card.html
I hope some of these tips are helpful and you learn to love your dies.