Marinate chicken: Mince and mash garlic to a paste with 2 teaspoons salt, then transfer to a large bowl. Stir in vinegar and oregano. Remove skin and excess fat from chicken, then toss chicken with marinade until coated and marinate, covered and chilled, at least 1 hour.
Cook chicken and rice: Cook chorizo in olive oil in a 12 inch wide 6 to 7-quart heavy pot over medium-high heat, stirring, until some fat is rendered, about 2 to 3 minutes.
Add onions, bell pepper, and garlic and cook, stirring until softened, about 5 minutes. Add cumin, oregano, paprika, 1 teaspoon salt, and bay leaves and cook, stirring, about 1 minute.
Add chicken with marinade to chorizo mixture and cook, uncovered, over medium heat, stirring frequently, about10 minutes.
Stir in tomatoes, beer, broth, and rice and bring to a boil, making sure rice is submerged. Reduce heat to medium-low, cover the pot with a tight fitting lid. Cook, stirring once or twice, until rice is tender, about 20 to 30 minutes.
Remove from heat and let stand, covered, 5 minutes. Discard bay leaves, then scatter pimiento or red pepper strips over rice.