One thing to note is that the caravan list does not show rogue regions. The number you can see will change all the time. From Libidizedd I currently have access to 48 regions. Kybcyell in the west, Valkyrja in the north, Mistight and Nebel in the south, Nimh in the east. It is a very wide range.
I think Libidizedd has the best location for caravan trading. Centrally located on the sea routes, but close to both shores. I can send caravans to eight different realms. If Dwilight ever fills up, Libidizedd could be a huge trading powerhouse.