GMath

Its quite likely that you are correct. It still would have been the classy thing to do.

On the occasions when I've had to address these kinds of situations, I do my best to steer the conversation away from the semantics of whether or not the behavior should be labeled as "bullying" or "hazing" or similar. Instead, I try to focus on identifying that the actual behavior that occurred is not acceptable in Scouting, and focus on tangible actions that need to take place to discourage the behavior from happening again. How we label the behavior is less important than recognizing that it is inappropriate and that action needs to be taken to correct it.

I'm understanding the discussion so far to mainly be about step 4 "take corrective action," which is wonderfully vague.

While the BSA does assign responsibility for handling these matters to the adult unit leadership, my point was that the BSA does not really provide a step-by-step checklist of actions to take in these cases. The specifics are left to the discretion of the (hopefully) trained and qualified adult unit leadership. Hence my suggestion to @MarkBrownsky to begin by talking with your son and coming to some consensus to what you feel an appropriate, constructive resolution would be in this scenario. Then, approach the SM and have that same discussion. I think you are absolutely right to expect transparency and follow up from the SM. And, while you could escalate this up the chain to the COR or council level, they're first reaction is likely going to be to refer the matter to be handled at the unit level (unless it is particularly egregious.)

No, its not a typical function of a Den Chief to rummage through others' personal belongings. The role of a Den Chief is to assist the Den Leader as directed, and to serve as a role model, resource and leader for the cubs in the den. What was the purported purpose of this "inspection?" I'd certainly expect a Den Chief to help educate the cubs and parents on suggested equipment to pack for an outdoor trip, as well as to provide some guidance to help make sure tents are setup properly and safely. But that shouldn't involve going through personal equipment without permission.

What do you and your son think the proper outcome here should be? The BSA doesn't necessarily dictate unit-level disciplinary procedures in most cases.

A District Commissioner is likely not the final authority on unit number assignment. If you're on the verge of starting a new unit, your council should have assigned you a District Executive ("DE") to help you with the process. This professional staff member should be tripping over themselves to answer your questions and resolve any roadblocks you face. Picking a unit number should, to them, be almost a non-issue. As long as the number isn't already in use by someone else in your area, I'd be shocked if they tried to enforce some arbitrary numbering scheme. Yes, there may be some computer system backend code that uses some other ID number for your unit, but that you should really have to deal with on day to day basis.

The BSA's insurance provides coverage for visitors to unit events, I presume that would apply here. Individual units rarely carry their own insurance policies. Note that you still have a responsibility to cover things like adequate supervision, age-appropriate activities, etc. I'm all in favor of trying to play nice with my neighbors and fellow scout units, but if you've identified this other unit as having a toxic culture, you'll likely be a lot happier if you just ignore them.