Guildhall is under Creative Writing, which is on the topmost row after Formalized Diplomacy.
You can't capture monsters, but the Monster Containment does let you build Monster Pits with your own monsters, and that prevent monsters from hitting your nearby stuff.
On the hyperlinks, that's a fairly tricky sort of text thing that would require a fairly sizeable engine extension to a component that we didn't design. It's definitely technically possible to do, but it could take use a solid 3-4 days, not sure.