Re eating noodles with one's hands- iddiyappam are eaten with the hands. The noodles are clumped in rough discs during the production process so you get coherent clumps of noodles which are then broken off and used to soak up the curry.
I'm wondering if the idea behind iddiyappam was an indigenous one, or if it was imported from another part of the world. The noodle dishes of Central Asia are always based on fresh, handmade noodles, which are usually much thicker in consistency than these ones. That, and the fact that noodles are almost non-existent in northern India, suggests that iddiyappam couldn't have originated from the Silk Road.
Well, it is possible that iddiyappam derives from falooda, which uses vermicelli noodles and can be found from Iran to Myanmar, but that's a sweet food and the noodles used in it are not the star ingredient.
Otherwise, I wonder if the concept behind this dish traveled to southern India via sea routes from Southeast Asia during the time in which the ancient Tamils were active in colonizing and trading there?