No
2012 Ram 1500 wheels will fit on a 2003 .
No, it will not fit.
NoNo
It would physically fit, but you would need the proper computers, sensors, transmission, etc.
They should fit 2003-2016
It is inside the transmission, on the valve body.
No.No.
1994 and 1995 only.
No. The control solenoid and sensors are not the same.
yes
It would fit under the hood, but the suspension will not support it, the transmission will not bolt up, the wiring is different, etc.
You need to put a little more detail in. What engine do you have, and what engine did the 99 have?