@Idiom : I won't be putting any init option stuff in this proposal. If the system is functional without it in the first place, it doesn't need to be here. Later additions can always be made to exploit synergies. Meaning, Toady could use guilds to implement all sorts of new ideas and mechanisms beyond what was initially proposed.
@Annales : Thanks for pointing out the omission. That was actually one of original items, but I forgot to put it up as the list was being organized.
@Shades : I've argued for more diverse "moods" in a couple of threads. The problem always ends up with 1: "what does a mood cook make?" 2:"an artifact cake." 3:"Wait, we can't have consumable artifacts!".
All in all, fixing moods would be a separate topic. It would help fix a weak spot in this sub-category of the proposal.
As it stands under the current proposal, a farmer that had a woodcrafting mood would make his artifact and go right back to farming. He would have the option to change Guilds (he is in House Ber and can stay there, or he can join House Rigoth). Whichever one he leaves/refuse will dislike him a bit. If he tries to do labors for both, he will end up making someone mad.
the actual mechanic for "choosing" would probably have to involve the relationships he has in his current guild, his skills, and his "likes and dislikes".
A few examples:
A novice immigrant has joined House Fer. He has made a single friend and a few acquaintances. He has a mood, becomes a mason. Now his legendary mason skill is far higher than his novice animal caretaker, and he won't be losing a lot of friends.....so he changes guild.
New Skill > Old skill + Social
One of the original 7 has been doing the farming for the fort for some time. He has been in House Ber since it formed. He goes into a mood, and makes a stone sceptor. He could join House Rigoth, but he doesn't...why? He has many friends in House Ber, and the Legendary Stonecrafter is impressive, but he is already a talented grower ,a proficient brewer, and a novice cook from embark.
New Skill < Old Skill + Social
Through years of work, a furnace operator becomes legendary. The dwarf isn't very social, so has no friends. She goes into a mood, and makes a Feathetree amulet. She chooses to join House Rigoth because she doesn't particularly like any metals, but does like Feathertree.
New Skill = Old Skill+ Social, so the tie breaker is likes/dislikes.
Just a rough outline. I didn't mention social ties to the new guild, but they would also apply to some extent. If, for example. the farmer in the 2nd example was related to the Guild Master of House Rigoth, it might be enough to sway him.