Hi Tangier,
For the best results in Final Cut Pro, you should turn on the Motion Blur feature under the "Motion" tab:
Final Cut Pro 7 User Manual
In Motion, the same feature can be enabled under the "View" menu. When exporting from Motion, remember to enable the Motion Blur feature also through the advanced Export options.
Motion 4 User Manual: View menu (search for Motion Blur)
I'm sorry about the crashes, you are not the first user to run into this problem. It seems to affect almost exclusively Mac OS X 10.6.x, and hopefully we'll get a resolution soon.
Hope this helped,
Gabe
Noise Industries, LLC
