I recently bought Rise of the Runelords Anniversary Edition to play with my group.
One thing I want to see is motivations for the player characters. Why are the PCs in a frontier town and why are they willing to risk life and limb chasing down bad guys?
My players are free to create to create background NPCs and Macguffins for their characters as needed. However these hapless NPCs/items will be under my control. So if your dear old dad gave you a +57 Sword of Killing Everything, expect that the bad guys will have stolen it before the story starts and you’ll spend the adventure path chasing it down. 
Here are some character motivations from TV Tropes that would work well for PCs in Rise of the Runelords. I linked to TV Tropes so that you can see examples of these motivations in other stories. Feel free to mix, match, invert and invent motivations as needed, as long as you can tell me why your character is willing to go out there and risk their neck.
- Undying Loyalty : A character is motivated by desire to help someone or something they care about.
- I Will Protect Her: A person has their entire motivation built around protecting a vulnerable person/town
- Small Town Boredom A teenager growing up in a small rural town wants to get away from it all, to the big city, or abroad, anywhere but the boring old Small Town.
- Only in It for the Money: A character does something heroic only for the money.
- Driven By Envy: A character wants something someone else has, and resents them for it.
- Failure Knight: A character failed to protect someone once, and is determined not to fail again.
- Family Honor: A character wants to live up to their family name, and bring credit to their family.
- For Great Justice: Good guys fight so that Justice Will Prevail.
- For Science!: A character wants to make discoveries with no real practical purposes.
- Glory Seeker: A character wants other people to consider him/her to be a Badass.
- In Harm’s Way: Characters want excitement and danger in their lives.
- I Owe You My Life: A character feels indebted to someone who saved their life.
- I Will Find You: A character wants to find a lost or kidnapped loved one, whatever the cost.
- Revenge: A character wants another character to pay for what he’s done.
- Well-Intentioned Extremist: A character has noble goals, but goes about achieving them ruthlessly.
Here are some other lists of motivations .
