Dancing is freezing up in playback

I have composed a 5 minute song-from USA Youth to Ukranian Youth.  The two verses represent empathy. The choruses are 6 characters who supposedly lip sing and dance. Doing two things at once, such as singing and dancing, has been shown to aide in brain trauma, which these poor Ukranian children have suffered immensly. 

I've got all characters dancing, but often the program jams and stops them from dancing in rhythm. I suspect it is too much information? I took out the visemes.  I have only one scene. In addition, I have a bunch of backgrounds that are imported as puppets. They all have both English and Ukranian words. My question is-how can I make this work?

I would include an example, but I haven't figured out how to simply take a portion of the song and post it.