I think those rib-like features are just a form of the so called flying buttress, they are quite typical of Gothic architecture. Yes, the St. Barbara Church is similar to the St. Vitus Cathedral in Prague, it was designed by the same architect, I mentioned it in the text. I´m glad this post inspired you to visit Kutna Hora :) There is actually one more iconic landmark of the town and that´s the Sedlec Ossuary. That place is even more unique. I will write about it soon.