Welcome to the club brother! Intimidating and intense situations, counter intuitive solutions and a painful aggravating learning curve! Makes a person long for that first year when all you had to do was feed and enjoy them.
The second year, in my opinion, is completely differant from the first year. Last year the goal was to keep them alive and get them built up for winter. Congratulations, by the way, you made it! Good job! The second year and from here on out it's about keeping them alive, SWARM CONTROL, and getting them built up for winter. Look at it this way, you obviuosly have a good start on the info necessary to keep them alive and getting them through winter. You, and I as well, have a LOT more to learn in those areas but we have the basics. So, your hives swarmed, CONGRATULATIONS! In the face of all the adversities, diseases, pests, pesticides, herbicides your bees not only survived they THRIVED! I hope that makes you feel better. That was the intent.
How many swarms have you caught this year? I repeat, YOU CAUGHT. How cool is that? You've had some success with that and you NOW know what to do when it doesn't succeed, you combine. Again, GOOD JOB! To answer your question about preventing swarms, I'm trying to get that right myself. Here's what I'm trying, pulling a frame or two of brood to reduce population, making sure the queen has room to lay in (keep the brood chamber from getting plugged up with honey or honeybound). I'll inspect once a week, pulling frames as needed and keep my fingers crossed. Sorry brother, that's all I've got. Ask me again next year and hopefully I'll have more to give. I will say that I doubt there is a step by step, do this on March third, kind of thing, but if you run across one PM me immediately! Ted