Cool, thanks for the time and advice.
I opened up the animation QT file like you said and it said that the data rate was below 100mbps. To be exact, it says 26.52mbits/s.
I also tried converting the animation as you said in Compressor using the ProRes422 codec at HQ (and at regular ProRes), full size, 24 fps (and multiple other compressions) and the file still has the same choppiness as it did in its original form when it was at 10fps. As far as I can see, it pretty much looks the exact same on both QT and FCP.
So, yeah. Guess I’ll keep trying new things and hopefully something will work…