House of Humanity resonates with me, but really because of my personal feelings about what the guild means. I think House of Communion, House of Community, or House of Care/Caring would also fit really well with this concept. My personal concept, however, ignores what I view as the decorative aspect of the guild, the adventitia to the core concept: the individualistic expressionism (“Hufflepuff at Burning Man”) - which I do recognize is important to the CREATOR of these concepts, as well as other members of my guild.
Also, @Viviane, I agree that purely based on sound, “Creation” sounds better than “Creativity”. When I first read this post, I thought about mentioning “House of Ideas” for Thornmouth, but I actually that would be a better fit for Flinterforge!
EDIT: I also like the connotation of “Creation” as in the entirety of the material world, (e.g. “God’s Creation,” “what in Creation?!?”) meaning the balance of raw materials and finished products and everything in between.