1. I don't know if this is the right one, but there is a dead guy outside of the shadowdragons lair that has a lot of treasures on him.
2. Talk to the gravedigger, just north of where you found Tirdis.
3. No, the kensai cannot wear armor, and he isn't supposed to tank. You should let him/her attack monsters at their backs, and let another fighter be attacked instead of the kensai. The kensai does the most damage of all classes (well maybe not a kensai/thief

), it is the most effective fighter in the game. Some people think the monk is better, I don't know, but the kensai does the most damage.