I don't know if it would do anything with a thumb drive or anything else that requires a host port. For a microUSB socket, there are 5 pins, of which 1 is unused when you wire it to a regular usb dock connector like this one. I haven't looked at the pinout posted, but it's possible that 5th connection is to toggle/enable host mode on the Tab. If I get a chance I'll plug in an external drive and see what happens.
As to how I shoehorned the micro socket into the dock port connector, it just required an X-acto knife and some super glue. Soldering on those tiny smd pins is a pain, so if I make another, I'll etch a small pcb and mount it that way.