Wow, you act like you've had mice all your life! You're doing everything right! One thing I would say is that you should also give them lab blocks with the mix. I too use the fiesta mix but I add oxbow young rat and mouse food so they can get all the nutrients they need. I would also recommend, if possible, to get an aquarium-like cage for them instead of the critter nation type cages. Mice can actually get stuck in the tubes and bars fairly easily. I have a 29 gallon long tank with a mesh lid (needed for protection and ventilation) which is secured with cage clips. They do fine with that
I don't think mice can catch your cold, but if it's bad enough you may not want to handle them too much, just to be safe
. Good luck with your babies! If you have any other questions for me feel free to ask!!