Create new creatures instead
these two creatures are existing 18649, 33251 in the core Monica apparently is supposed to do an emote during a fight in old hillsbrad (lol) The DK trainer is for the tournament server (so it could serve a purpose too)
So yes, they are almost useless ingame but it might be better to create other creatures
Not only this, half of the vendors have no inventory, the NPCs and game objects are just copied from the core. You need new NPCs and game objects explicitly designed for the guild house, with new names, custom inventory etc. This is much work, but in this state the module just looks half-baked to me.
This is not an issue. This should be closed
You can modify the NPC's to your liking. New version has better versions of already existing NPC's with revamped new ones.
I think it can be customized, actually, I feel that the module needs a few tweaks, however, for now I think it works well. I wouldn't want it to be on the gm island, however, I don't see it as bad either. But if you want to make modifications, I invite you to open a pull request with the changes that were made lately.