There is a chat pad that can connect to the microphone port on the controller or you can just use a usb keyboard (doesnt matter if its wired or wireless)
The analog on a Xbox 360 is the analog sticks (left and right of the pad). You have 1 d-pad (digital pad).
Fraid Not
NO, the xbox 360's controllers are wireless and usb, unlike the xbox which is a different connector.
You need to hack your save file and bind a key on the chat pad to "toggleconsole" as well as, obviously, a chat pad. However, this disables some achievements.
Yes you can plug in a standard USB cable keyboard, great alternative to buying a pricey chat pad or typing it all in letter by letter
plug it in as you would a controller.
The least expensive dance pad controller for the xbox 360 is a "soft pad." They usually run $15-$20 retail. Keep in mind that they are inexpensive because they break more easily.
Press up on the d=pad (directional pad)
yes
Up on the D-Pad
13 (16 if you include each direction on the D-pad)
Q on PC, D-pad Up/Down on Xbox 360, and D-pad Up on PS3.