Remove membrane from back of rib slab; cut into individual ribs.
Coat ribs with spice rub, cover and refrigerate for at least 3 hours, but preferably overnight.
Place seasoned ribs on broiler safe pan and broil until browned, about 20 minutes, turning at least once.
Combine bar-b-que sauce, coffee, hot sauce, Worcestershire, mustard and celery salt and heat over medium in a small saucepan until thinned slightly and warmed through, about 5 minutes.
Add beans, sauce and bell pepper to slow cooker and mix to combine.
Place broiled ribs atop beans, cover and cook on 'high' for one hour and 'low' for an additional 5 hours.
During the last hour of cooking, baste ribs with more bar-b-que sauce.