through my research i have found that the most likely reason for my steering wheel vibration while braking is a warped front rotor. However, the braking is extremely smooth and very strong. Could this be the rotor, or is there something else that could cause steering wheel vibration?

 

If it only happens when braking then I think you diagnosed it correctly as warped rotors. If you replace the rotors, make sure your calipers are working correctly or you will soon warp the new rotors. If you are on a tight budget it may be only one rotor that is warped causing the vibration. If you find a caliper that is not working correctly start by replacing the associated rotor. When the caliper can't move the way it is designed to move one of the brake pads often rubs constantly leading to excess heat, warped rotors and increased fuel consumption. Take the car out for a short drive just a mile or two and don't use the brakes excessively then feel near the center of each front wheel if one of them is significantly warmer then that could indicate a stuck caliper on that side. Good luck.

To answer your actual question: Steering Rack, Alignment, Ball joints, Suspension bushings, bad tires, wheel bearings, anything loose in the front end MIGHT cause some vibration.

 

Geometry is pretty spot on. Axles are also an issue for vibration, but you'd probably feel that in more than just your braking.

 

"warped rotors" are a symptom of excess play in the rest of the car.

if you have vibrations you can feel thru the car, then most likely rack end bushing primarily, then pinion adjustment, and tie rod balljoints. upper and lower balljoints also probably worn if those are worn too. also steering column joints may be loose.