Add cold water to cover by 2 inches and bring to boil.
Remove from heat; cover and let stand 1 hour.
Drain beans.
Heat oil in same pan over medium-high heat.
Add onion, celery, and carrot; sauté until vegetables begin to brown, about 10 minutes.
Add rosemary and thyme. Return beans to pan.
Add enough cold water to cover by 2 inches and bring to boil. Reduce heat to medium-low. Simmer beans uncovered until almost tender, about 45 minutes.
Add 1 teaspoon salt. Continue to simmer until beans are tender, stirring occasionally and adding more water to keep covered if necessary, about 45 minutes longer.
Add raisins; season beans with pepper. Cool. (Can be made 1 day ahead. Cover and chill.)
Preheat oven to 350°F.
Sprinkle short ribs on all sides with salt and pepper.
Heat oil in heavy large wide ovenproof pot over medium-high heat.
Add short ribs in single layer and brown on all sides, about 12 minutes.
Transfer ribs to plate.
Add onion, carrot, celery, 2 thyme sprigs, and garlic to pot. Sauté until vegetables brown, about 10 minutes. Return ribs to pot in single layer, meat side down.
Add broth, vinegar, tarragon sprigs, and remaining 3 thyme sprigs and bring to simmer (broth will not cover ribs).
Bake uncovered until ribs are tender, about 1 hour 45 minutes.
Using oven mitts, transfer short ribs to stove top. Tilt pot; spoon off fat from surface.
Drain bean-raisin mixture.
Add cherry peppers and drained bean-raisin mixture. Simmer until sauce thickens slightly, about 15 minutes. Season with salt and pepper.