Sure - that's true. We cannot mandate anything really. In almost all cases we can simply to tell people what we expect and to tell them when they are not welcome and ask them to leave. I suppose that one could get into situations and discuss calling the police to forcibly remove people from the premises - but I hope that never happens.
But, really, I think these are all technicalities. In most cases, folks want to do the right thing.
In one of my several uniforms, I am a Cub Scout Day Camp Director. Our camp, like many others, is held at a county park. While we pay a very high fee to use the park for the week, there are portions of the park that are still open to the public. We do not tell the general public what they may do in the open areas of the park, but we do not allow them to mingle with the cubs.
What I think the gist of this thread is about, is not a scout event in an area open to the public, but parents/family friends who are attending an event that is only scouts, such as cub family camp, day camp, or some troop outing. In that specific instance, registered or not, YPT rules such as no one on one apply to every adult present and participating in that event. We frequently have parents volunteer for the week at day camp who are not registered leaders. They are all required (National Camp Standards) to take an in person YPT class, and must abide by those rules or make the choice not to participate.
BSA cannot always compel a non-member to leave a place that is not owned or controlled by BSA. It is indeed a free society, and the unit can leave, if they have a mind to do so, but they cannot always compel someone else to leave, or to follow their rules.
I'm a little out of touch since I haven't backpacked in a few years, so I'm not the best subject, but with question #1, are that many scouts (youth) using hiking poles? We found they (youth) just end up dragging them along more than balance their weight.
#2. Yes, two man tents like the REI are common for two adults on backpacking treks. The 2 man I own and took to Philmont for two adults is about the same dimensions as the 2 man REI.
I have certain requirements for backpacking tents and I liked the REI. The ONLY reason I wouldn't consider this REI is because it's not self standing. Self standing tents set up faster (in the heavy rain) and don't rely on firm ground to stay up at 3:00 am in heavy winds and rain. What I like a lot about the REI are the doors and vestibule on each side. Multiple doors allow a quick entry by both occupants at the same time instead of one occupant waiting on the other while blocking entry taking off muddy boots. The vestibule on each side provides a dry place outside the tent for each occupant to store muddy boots and wet rain gear. Its a nice tent.
I have nothing against tarps, we used them when I was a scout. But I find a tent provides a little-bit of privacy from the scouts. I know, it's really not much, but after a long full day with them, every little bit of "out -of-sight" is "out-of-mind".
From our experience in a backpacking troop, backpacking tents take a beating from scouts, so the slightly lower quality tent that sacrifices a little weight usually goes a little farther. Kelty level tents provides descent quality for scouts at a reasonable price. Also, while a few of our scouts purchased a single man tent for weight, many found they would rather tent in a 3 man Kelty type tent for the camaraderie. In fact, my 3 man Kelty backpacking tent became the most popular with the scouts so they could play cards at night. It was a great tent for scouts in Norther Tier where space was very limited. Adults tend to take better care of their tents, so they purchase higher end tents like REIs.
My understanding matches @T2Eagle & @Sentinel947.
When you're at an event organized as a Scouting event, BSA YPT rules apply. Of course a CO can impose even more restrictive rules, but they cannot waive any BSA YPT rules. If a participant decides that they don't want to follow the BSA YPT rules, then they can leave the event. It's a free society and no-one can compel anyone to attend the Scouting event. But, while there, we do require that those present follow the rules.