While I appreciate the modding possibilities of the client, I don't appreciate the botting too much that's done with it. I think owning some hearthling NPCs would be a nice addition to replace that automation part of custom clients to some extent, and one of the big things that Haven is still missing that would make it out of this world.
If we could own PvP and bot work capable NPCs, that would be real neato. A lot of survival games these days have this mechanic in-game.
Most importantly an NPC to do farm work, an NPC to do herding and to do PvP. Either assigning them to a workstation, where they commit to 1 particular task or have them join your party, such that they follow you and follow a basic AI aggro and movement setting that you can adjust anytime, such as
* attack on sight
* protect me (attack anyone who aggros the owner)
* defend (don't attack anyone unless attacked)
* hold position (have them stay where they are at and only retaliate on being attacked or if someone gets into their attack range)
Now if you could also sell and trade these NPCs, that would be even more fun.