Sorry,LOL, the sting pheromone smells like bananas to us, not the bees. Doesn't work the other way round.
You are correct in that incoming nectar and moisture analogy. My thoughts would be you are overloading. The bees are bringing in what they can deal with based on hive division of labor, you are dumping it on them. ( not knowing how you are feeding but) JMO
I believe the right queen line would do what has been posted here. My thought line is this, if you like the queen, go with her till you have no option while trying some things. Re queening is like surgery,,,,it may be a simple process, but you never know the complications that will arise. You could be right back where you started from and a few brood cycles behind.