Hi:

I am a Final Studio 2 user and, yes, you can export from Poser as a QT movie and then import same into the Final Cut timeline.  If you render to black from within Poser (for alpha channel)you will need (for superior results) compositing software (i.e. Shake, Boris, Final Effects, Combustion, etc.) to remove the background and insert another for use within the Final Cut timeline.
I have tried exporting as individual PNG files as described above but have found that Final Cut sees each frame within the sequence as a prolonged finite duration that exceeds the original.  I suppose that Final Cut is assigning the defafult duration that it uses for all single images (i.e. jpg, tiff, etc.)  It is equally assumed that one could nest the frames and adjust the their durations but that adds extra steps to the process.  At least at the present time, I have not noticed any advantage, other than the ability to make finer tonal adjustments to individual frames, to exporting as PNG.  The render time for the PNG's is slightly shorter but once you add the needed adjustments in Final Cut you're back to square one in terms of work flow and time invested.  Now, I must admit that I may be missing something in regards to the advantage of the PNG export and its subsequent import into Final Cut and if so, I would appreciate some enlightenment.