Yes, you can. It requires the TV screen
Wii Fit, definitely
You don't need the original wii fit software but you definitely need the wii fit balance board!
No. The Wii U controller will only be compatible with the Wii U.
The Wii U is compatible with Wii games. There is no difference in the disk sizes. (Be aware that the Wii U does not support Gamecube games.)
No. The Wii U will have the Wii U GamePad (tablet) and it will come with another console. You cannot use your old Wii with the Wii U. You need to use the new Wii that is included in the package.
The Wii U gamepad cannot be used with the Wii.
No. The Wii U gamepad is not compatible with the original Wii.
No.
No the Wii U is an individual console itself
Wii U games cannot be played on the Wii.
No you can't and its wii u, not wii you.
The Wii U is a standalone console and does not require the original Wii console.