Hi Luoy
I did the tests as you suggested.
1. Working okay on test site but still broken on my own site.
2. Question. If I use the generic image field and name it '_featured_image' will WooCommerce recognise this as the product featured image? I mean that image will appear in the standard WooCommerce Cart view?
3. Yes it is also broken on your test site. I created new product called 'Test Product' through the front end form. Then I added it to the cart. If you go to the View Cart page then you will see that the product title and image are not clickable. This is the same problem I have on my site.
4. Yes I now clicked "Validate Option" and that works thank you.
Regards
Robert