Well, to be fair, the co-ordination of stage and pit is ALWAYS something that concerns conductors in Act II of Boheme, and indeed some of the critics had commented that even under Bychkov the children's chorus was a 'bit out' at the opening night. But you are right: this was only a small slice of what a real conductor has to do. Nevertheless I enjoyed the massively exaggerated climax towards the end of the act and Musetta's tune.
The whole act must have been one of the longest ActIIs I have ever heard, which made it sound too deliberate - apart from when it came into its own at that moment. This was mainly as a result of the fact that CRH had still not got his flamboyant gestures under control and therefore everything had to slow down to be in sync with these!