Re: How often should we be opening the hive?
putting your judgmental and argumentative comments aside, the OP is trying to figure out for himself what is 'regular' inspections.
He wants to know if once a week, once every two weeks, etc... is an appropriate interval for checking the hives without unduly interfering with the colony or causing some rukus he, the OP, doesn't intend to happen.
I can say that I once spoke to Dr Marion Ellis, of the University of Nebraska, who is a very well known bee researcher and beekeeper. He does not think going into a hive too often is a good idea either as it can interrupt the hive environment leading to chilled brood and other issues.
I agree that if one wants to learn from seeing the bees in action on a constant basis, an observation hive is the better way to go and will provide the best opportunity to see all you can see of hive behavior and activity.
However, to repeat myself, NONE of us are the authoritative answer here. You are free and encouraged to make your own informed decisions as it will work best for you and your bees.
No, I am NOT a bee "Keeper". Anything I post is just my opinion. Take it easy and think for yourself.