I'm looking for a mod that allows me to add more than 3 traits (would also be nice to edit legendary traits) and a mod that lets me get both the certificates for being a pirate and a noble. Any help would be appreciated.

Not sure about infinite traits (or adding more than 3 traits for that matter), but I'm pretty sure Grim's Core mod let's you edit Legendary traits and sim factions (so your sim can be a pirate or a noble - although I'm pretty sure your sim cannot be a noble and a pirate simultaneously, they can just switch their title from pirate to noble and vice versa if they have the title in their inventory). Included some screenshots below.

thanks for the info! came back to this game after a while only to run into the same problem and almost forgot i had made this post. its quite hard to find mods for this game but i'm glad people are still posting on here. maybe someday someone will make a mod for traits like in sims 3 and 4. might work on it myself if i learn more about coding and modding for this game