For the Armor Breaking quest you first need to talk with the blacksmith Knocky in Ebron to get the recipe for the Katryx Blade and for the info that the Katryx Ore is at the Dhranholl Mine. When you go to the mine afterwards and talk to the guard at the entrance he'll tell you that you need the permission by Walcot to get in. Walcot is at the Whitestone citadel, not Calterburry.
The first political meeting with Begus is in the big building at the Red Keep in Central. Go there after arranging the meeting with Theremis in your castle.