printing over the zipper is very tricky and best to use a custom palette. Cut some palette rubber, cardboard, etc. so you can have a channel for the zipper to fall into. This will help to smooth out the material for a easier surface to print. Make sure you test as this is tough printing.
For the left chest print get yourself a 5X5 tile from the hardware store. Tape with masking tape and line your screen/image to this. Raise your off contact appropriately. Print as you normally would. This will offset the printable area from the zipper eliminating off contact issues when printing.
For the palettes you can see what I am talking about here
Zipper Hoodie Pallets
Good Luck.