you want 0 (zero) accuracy as a tank. for every point you have in accuracy your missing out on a point that could be placed in mitigation.
Normally, maybe. Most of Juggs' damage comes from abilities with 90% accuracy (rage builder) and we have crap for threat right now to begin with so if you miss with these your threat will suck. Please go back to your Sin/PT and speak only for your tank class.