Yes, absolutely. You are free to ship with the carrier of your choice (UPS, FedEx, Purolator, etc.)
Only the return of the PickPack is via Canada Post.
No. PickPack handles all the reverse logistics, receiving, inspecting and replenishing your packaging.
What happens if the consumer doesn't return the PickPack? No financial impact for you.
The consumer pays for the PickPack option at the time of purchase on your site, so you don't cover any losses in the event of non-return.
For the bag: affix the shipping label to the flap, which will seal the opening.
For the box: place the label on the opening flap.
See examples in photo below.