Took me some time to figure out the trade mechanic, but I do understand it. The goods in question is Frankincense. The only sources of the goods that is in the region close by is in of Syrtica and Cyrenaica in africa, and since they are produced locally one province inland from the coast, the only w...

Don't take me granted, but it seems like that the possibility with the raids is dependent on how loyal the province in question is. Once the loyalty of the province is above 90+, I don't recall getting any raids at all.

The devs should implement an option to change the capital.
I wanted my region capital in southern Iberia as Rome in the most southern coastal gold province, but instead it just selected an inland province, with next to no trade or wealth possibilities

Depends on the situation. Usually I have a specific goal for the province so I pick whatever category that matches. In some cases tho, when public order is low and I need a way to decrease the unrest, or when I know there is an 4x times more efficient building to get (usually at something 20+ pop wh...

To cut it short, conquered enemy place in africa to get cheap access of rare resource for Rome that was required for some high level structures. The resource is one province from the coast and somehow the ancient people can't haul the goods to the closest port and send it to Rome. The actual trade r...