Hi,
I heard from a friend who is going a different program that he has a lot of pedalling exercises, skill training. In my sessions, there is none of that. Are there training sessions on Zwift that are not there to increase your FTP or whatever but just increase your cycling skills?
Would be ideal to do on the days in between 
Just riding would be my idea of improving your cycling skills but it depends what skills in particular you wish to improve.
Zwift won’t help with cornering, that I can confirm.
My buddy was asked to cycle standing with low cadence and low power. Another training he had to cycle with 1 leg.
Must be some exercises where you have to learn to pull as well as push.
Some of the workouts and training plans will have instruction to increase cadence, stand up, reduce cadence, etc. IIRC the Crit Crusher plan has a lot of cadence work. I don’t know of a way to search other workouts for this type of instruction?