> whereas, friends' daycare'd kids are sick all the time, constantly having runny noses and s

Probably just the common cold most of the time. My nose was runny through most of my childhood too. And kids are snotty - always have been - it's not necessarily a condition that needs to be fixed. If it's bothersome to you, then of course avoid group childcare.

Also, some diseases like chicken pox are preferable to contract as a child and gain immunity to then - since they are far worse symptomatically to contract as an adult.