I am in schutt all day and nothing like this happend to me. Not single disconect or other bug u mentioned for me since start of server.
I have found the steps of reproduction for the bug and i updated the post. Please read again
Issue only occurs for the dwarven Artisan quest when choosing the shuttgart path. The contact NPC in shuttgart is bugged.
It seems that Hitchi is not the only NPC that is bugged in Shuttgart. As I've seen on the forum throughout the day, a lot more people are experiencing this bug in Shuttgart at different levels. It seems that most of the Shuttgart NPC's are bugged and any quest that wants contact with one of those NPC's will make the client crash and disconnect every time the user tries to target npc/player/pet/himself. The only way to solve this issue locally for the moment is to discard of that quest until the NPC's are fixed.