Moving from indexed & folder-based to imported & tag-based

Hello, all.
I’m creating this post to ask for advice regarding a transition I’m about to make.

I have a DEVONthink database for keeping content saved from the web - bookmarks and PDFs - across a wide range of topics.
These are organised using folders/groups, which can go up to 4 levels deep.
All the content is indexed, rather than imported.

I want to transition to a pure tag-based approach, so that whenever I add an item, instead of having to think and specify a group where it should go, I will just specify the database and the appropriate tags.
Because of this, I think it also makes sense for the content to be imported into the database rather than indexed.

I have already created a separate database with which I’ve been experimenting this approach.
Now I would like to migrate the content in my indexed folder-based database. It contains approximately 2000 files and 424 groups.
I would like the folder structure to be converted to a tag structure (ordinary tags). For example, if I have the following 4 folders:

Tecnology
 |- Apple
      |- iOS
          |- Documentation

then I would like any items in the Documentation group to have the tags Documentation, iOS, Apple and Technology.
I am familiar with the Group Tags concept, but I would like to use ordinary tags instead.

1. Should I
   A) do these changes within the same database where this content is, or
   B) keep that database as it is and copy the content to the database with which I’m already experimenting with the “tag-based & imported content” method?
2. Depending on the answer above, what steps would you advise me to follow?
3. Is it possible to automate the process of tag creation and tagging as I described above, or would I have to manually create the tags and tag the items myself?

Thanks in advance!