Colony management, making lemonade

I think this falls in line with management. About 4 weeks back I noticed one of the colonies in my home yard was lacking young brood. Made a note that there might be a queen problem, I found what looked like an open cell.  First thought was they superseded her, (she was over a year old and not very good).  So I left them. Checked about a week and a half later, no brood, no signs of eggs or larvae. Gave them a frame from a different hive. Waited a week, no queen cells on the frame. So I figure there's a queen but just not laying. Again I waited until last Wednesday. No brood, no eggs, no sign of queen. So now what are my options. Something we should all think about from time to time. I had several grafts being made into queens, there are at least 4 virgin queens in mating nucs so getting a queen in a week shouldn't be a problem. And hopefully next year, from March to November we'll have queens all the time. Considered different possibilities, I really wanted a mated queen to put on the box in a cage and check the reaction. One can determine quickly if there is a queen in the box like this. I decided to go to a different yard and pull a frame of brood, at least with brood in the box the pheromones will suppress laying workers.  And the brood will maintain the population somewhat. While in that hive I spotted the queen. She too was a year old, and although still laying, I had planned to replace her in November. Made a quick decision to catch her and see if the first box was queen-less. Took home the frame of brood, put the queen in a cage and checked. Bees immediately came up to check out the queen. Fed her through the holes in the cage, were not aggressive just welcoming. So there was not a queen. Time to make some more decisions. Do I take this queen back to her old home? Do I leave her in this box in a cage overnight? Maybe for a few days? If I leave her then take her away will they suddenly panic and start making cells? (Now that''s something I might try to experiment with).  So here is what I decided. The second colony is very strong with four frames of brood and a lot of young larvae. I decided to leave the queen caged for two days in the first hive, check for any queen cells in the second colony and go from there. Meantime my grafts and virgins can be doing their things. Went back and checked the second box, at least 8 queen cells. I figure I'll leave them alone and create a bit of a brood break. In the first box I decided I'd release the queen after the third day but also after doing an oxalic acid treatment. There is currently no brood in this hive so it should be quite effective. Pulled out the queen, put her in my pocket and gassed the hive. Waited an hour and put the caged queen back in. The next morning I let her out, she ran right down between the frames. I'll check this box in four days for brood. In 11 days or so one of the capped cells will emerge as the new queen, in hive 2. So on day 9 or 10 I'll do an OA treatment there.  Will still be some capped brood but not a lot. Here is a prime example of why a beekeeper should have at least two strong colonies of bees. From the misfortune of losing a queen, I'm using the time to replace a weak queen and treating two hives for mites. Making some lemonade from what could have been bad.