Abs can be worked daily or every other day as you choose. You don’t really need to train forearms independently. Forearms get worked out during pull movements. When you do shrugs, deadlifts, pull exercises try using only the first two digits of your fingers to complete exercise this will help build forearms faster. Hammer curls and reverse bicep/tricep exercises work forearms. If program is working for you continue using it. Personally I feel you’re working your bis and tris to much. Biceps get a workout with pull exercises. Triceps get workout with press exercises. Your legs are your biggest muscle group. I would work them at least twice a week because that will help you get the most growth.