@Gheez: what exactly are the following persons in your list: Psychian, Monarch, Bard, Merchant and the difference between being a Jacoban Priest or a Peteren Priest?
I've just re-read that article I linked to. The persons are the characters that you can choose to play to complete your quests.
I'm not sure that I understand what you are asking, so hopefully I'm answering you correctly.
The physician (edited my original post to correct spelling) is the doctor. You see this one in the videos operating something that looks like a torture chamber rack. He'd be creating potions and curing the sick.
Monarch is the king or queen. Bard is the songwriter and storyteller. Merchant buys and sells things and trades with other countries.
As I understand it the main differences between the priests are those of how they interpret their faith. The Jacobans are good at reminding their followers of the hell that awaits the sinner -
fear god - and have amassed great wealth within their church. The Peterans preach more forgiveness -
god loves you - they don't have much money and take a more gentle approach with their congregations.
Hope this helps and answers what you were asking.