Daburus

I always looked at it like putting a spoiler on a race car. Race cars have spoilers to generate "downforce", which pushes the car down onto the road at high speeds, improving traction and stability, allowing for faster cornering and better overall control by counteracting the lifting force created by air resistance at high speeds.

He was in charge of the money being made coming into the port of Gulltown which is controlled by a branch family of House Arryn

Stanis is currently the Master of Ships

Jory bent down for him

Doesn't he need to go to school?

What was the point of writing a letter if he was going to deliver it? Especially since he wanted to hand it over to Maris himself.