Re: treatment free beekeeping - the risks
Beelosopher, I restarted with bees 6 years ago, after a year of reading and preparing. Subscribe to one or both of the journals, that will be a big help, as is this forum.
I started with two hives, with the intent to grow over the years to 50ish, experimenting and studying along the way. So the short answer is that you can keep as many or as few treatment free hives as you want.
Some treatment free beeks will treat for Nosema, some will give HBH, some will practice IPM and break the brood cycle, others will use drone frames, removing and freezing when full.
Personally all I've done is buy treatment free bees. Over 6 years I've medicated for Nosema once (because that's what we did each spring in the old days) and given HBH in one or two feedings. Seems to me the key is to develop a plan and work it. When absolutely necessary, modify it. I have just never treated for mites, don't even do mite counts. I know I have them, but the bees are taking care of them, so why bother? And that approach is heresy to a lot of folks.
"If all you have is a hammer, the whole world is a nail." - A.H. Maslow