What codec and resolution are you using out of Final Cut…?
(does the resolution fit your object sizes in Cinema 4D…?)
In Cinema 4D put your movies and textures into a texture-path Cinema can find…
(open Cinema’s Preferences / Texture Paths / select your Path..)
Regarding playback in the Viewport / in the Material in the Attributes-Manager
open the Editor Tab and check Animate Preview…
Otherwise use a JPG-Image-Sequence as your Texture, that might improve
playback-speed in the Viewport considerably…
Regards
Nolan