How many types of duty can a character start out with? I have a player in my campaign that used his character's 10 duty and split into two types (5 points in each). He says the rules allow this, but I didn't press the issue at the time during our roll20 session. Reading the AoR rules, I tend to lean that one can only have 1 type of duty, but it really doesn't directly state so, at least not clearly.

Along the same lines, would someone be able to have more than one type of duty further into the campaign?

According to page 47, of the AoR Core Book a character can start with dual duties. So, two maximum to start with.

Here's the quote...

"The PC's Duty is equally split between two different areas of focus, and success in either is good for increasing Duty score."