even a small amount will effect the clutch.
however,
if cleaned promptly/thouroughly with "brake clean" b4 assembly, no.
if not cleaned, will reduce the ability to disipate heat, promote hot spots, and possibly warp the disc. will create hot spots on the pressure plate as well. clues for that would be bluish color on it's mating surface in that event.
yes , it can damage the friction material
no one has ever told me it would.
How much? If saturated, will cause it to slip, heat will glaze surface of disc. Spray down w/ aerosol brake cleaner and let dry thoroughly.
its a hyundai santa fe 2007 model