Here are some ideas for more XP at level 13.
From the image, you haven't finished Treated like Cattle, which can be done at level 9. The only trick to it is knowing the recipe to create a second potion to cancel the polymorph on both cows. There is a book that tells you how to do it. However, to read it, it requires a character with both Scholar and Mystic Traits. You have Fain, who happens to have these, so no problem for you. Otherwise, check YouTube and you should be able to find the recipe.
Another option for picking up some XP is the trolls. They are immune to physical CCs. However, both are vulnerable to being shocked and stunned. Set up you party for this and then just keep the respective damage type applied. At level 13, it shouldn't take too long to bring them down.
I don't see Opposites Attract or The Merchant in your list.
Another option for more XP is to pick off the Magisters in Driftwood. The two with source hounds on the west side of town will attack unless you persuade them otherwise.
