Q: Can we not delete shipping addresses from Apple Pay once submitted?

Hi ..

You can edit the zip code.

Tap the Apple Store app then tap Account at the bottom of that window then tap Account Settings then tap your shipping address to tap the zip code to edit the tap Done.

This only allows you to fix the shipping address associated with your Apple Store account or Apple ID. This does not allow you to fix or delete a shipping address entered while using Apple Pay within an app.