Every single teacher I've ever worked with have all given me similar advice about breathing during TCC form practice:
First, they all tell me it's a really good idea. They all highly recommend that I breath during my practice.
Second, they all say not to attempt to tie a pattern of breathing to my movements.
The only exception to this rule has been on the named posture, "Beginning" (qi3 shi4), more often referred to in my circles as "Opening".
By any name the prescriptions for breathing during that named posture have been the same; inhale when the arms are lifted, exhale when they come down.
After that the advice is always to breath naturally, not to force an inhale or an exhale to try to make them coincide with a particular movement or energy.
I have been told, and have found it to be quite true, that my breathing will naturally evolve to match my movements as I practice more frequently and that attempting to do otherwise will only slow down my progress.
So relax, breath naturally, smile and let the energy flow as you move.
Since it worked for me that it the advice I now give to my students and it seems to work quite well for them too.
I hope this helps.