Hi @Dawid,
It’s quite nice to see the customization you did with your passbolt! That’s indeed an interesting idea.
In the future, we want it to be possible for the user to select the columns that are visible in the UI. Tags could definitely be a part of it. I created this entry in the forum backlog so that other users can discuss it https://community.passbolt.com/t/as-a-user-i-should-be-able-to-see-the-tags-associated-with-a-password-directly-from-the-grid-view/1484
Regarding how tags are managed during an import, this is going to change soon with the release of the folders feature. This feature will actually be closer of what you are trying to achieve with tags, since it will be nested.
Thanks for your suggestions!