Sorry the math must be off somewhere as they can't go from no queen cells to capped queen cells in 3-4 days... Were those 10 capped cells found in the parent hive or the first split? You still have queen in the main hive, right?
10 cells in the nuc seems excessive, but I doubt they will swarm. Not much you can do about them now, I doubt there is an easy way to separate them if they are all on the same frame.
As for the killed queen- perhaps (based on your capped cells there) they have already started making queens when you introduced the cage? As I said the timeline is not very clear, queen cells don't just pop up and get capped overnight...
10 cells in the nuc seems excessive, but I doubt they will swarm. Not much you can do about them now, I doubt there is an easy way to separate them if they are all on the same frame.
As for the killed queen- perhaps (based on your capped cells there) they have already started making queens when you introduced the cage? As I said the timeline is not very clear, queen cells don't just pop up and get capped overnight...