Motion and Depth Passes
When rendering motion vector pass and depth pass in maya, try to always use 32-bit formats and choose 2d motion vector and camera depth passes.
In Nuke we would be using the vectorBlur node for motion blur and zBlur for depth of field.
Another tip is to associate motion vector pass to every render layer because maya will offset the frames in order to calculate the vectors, which might cause positional problems between each render layer.
Hope these tips help!