Re: How often should we be opening the hive?
This is only my second year, but it looks to me like there are some pretty good reasons to look in fairly regularly.
1) When a flow is on you need to check to see if they need more room or if you have honey that you could harvest.
2) When there's a dearth of necter you might want to check to make sure they don't starve.
3) If you live in an area where SHB are a potential problem, you need to make sure they aren't getting out of hand - there's no way of knowing other than opening it up that I'm aware of.
4) If they requeen for any reason that is all well and good, but if the new queen doesn't make it back from mating, and you don't take action you might have to deal with a laying worker when a frame of brood would have taken care of everything.
5) If you don't do inspections you might miss chances to make increase and prevent swarms - or at least minimize their impact.
I probably pester my bees more than I (or they) need - but it's not as much of an issue now that I have a few more hives. I say that as long as you are in learning mode get in there (or don't) when ever you see fit. When you are no longer in learning mode - well, I guess you'll be wanting a good rocking chair - or a new hobby.