1. Is the individual agilemultipleseller able to add his carrires by the price or weight and country or state in the administration panel (BO)??? - 'cause the additional positions in the table of carriers don't show up by me
2. Is it possible and HOW to do it, to be able to configure the carrier by the country and state, as You've written, and not only by the zone???
The seller can add carriers.
Each carrier seller can choose delivery zones(not country/state).
I do not remember we have any place indicate that you can set carrier by country or state. you can only configure carriers by delivery zones. and you and assign your country and state to zones.