You are stating a lot of things that are unproven. For the business margin issue, there needs to be some kind of assistance plan to make up the difference in revenue. That would be cheaper for the government than paying all the unemployment.
The 6 foot thing is a lot more scientifically sound than you make it out to be. The entire world is using that recommendation (2 meters in metric countries). You are also talking about completely uncovered sneezes and coughs. The droplets fall to the ground relatively quickly which is how they came up with the 6 foot thing. A ceiling fan is likely to force them down faster and how many places have AC that is like being in a wind tunnel like you describe?
For the concession issue, first what does hand to mouth have to do with anything? Wash your hands or use sanitizer before eating. Like with restaurants there would have to be some kind of assistance to make up for lost revenue due to the reduced capacity or not selling concessions.
Nothing outside of a true lockdown where nobody can leave their residence for any reason for probably a month unless they are wearing full PPE would "keep people safe."
We need to come to terms with the fact that nothing, including the current "safer at home" orders is going to prevent further spread of the virus and more deaths. We also need to come to terms with the fact that doing the current measures is not a sustainable strategy and does lead to some level of death as well.
Studies show that the majority of spread happens inside the home or in workplaces with people close together in confined spaces for prolonged periods of time. I believe these studies because how else can you explain the continued spread in Italy and Spain long after the lockdowns were started? The curves in neither country indicate a rapid decline in new daily cases.
I haven't had time to analyze every single outbreak in the world but from a 40,000 foot view, the areas with major outbreaks seem to have a few things in common. The areas are densely populated, have relatively high usage of mass transit and, possibly most importantly have more compact/dense living spaces, many times with multi generational households.
In the more rural areas of the US, the major outbreaks seem to happen in nursing homes and meat packing plants, not a among customers at Walmart. Sure there will be some spread at Walmart and other businesses which provide seeds for the nursing homes and meat packing plants but if you screened the people entering nursing homes and dense workplaces like meat packing plants you would pretty much eliminate the outbreaks in those areas.
The stated goal of all of these measures was to flatten the curve and prevent overwhelming the healthcare system, not to "keep people safe." Outside of the NYC metro area and a few select metro areas there hasn't really been an issue. Even in Florida, outside of Miami-Dade (and maybe Broward) there isn't really an issue anymore. In the last week, Miami-Dade accounts for 37% of all daily new cases in Florida while only representing 12.6% of the population of Florida.
As to how this relates to WDW, WDW was absolutely packed until the closure on 3/15. There were clearly a large number of people already infected at that point but the cases were not known due to either being asymptomatic, mild or the testing capacity was not adequate at the time. However, I have seen no report of a significant number of cases directly tied back to WDW in mid March. As with a rural Walmart, I'm sure there was some spread that happened, it just doesn't appear that there was what would be considered an "outbreak" at WDW.
My sense is that if you eliminated the densely packed, long duration queues by using some kind of virtual queue system (either all FP+ or some kind of boarding group system that worked like the old FP system for standby), suspended parades and fireworks, encouraged hand washing/hand sanitizer and put into place enhanced sanitizing of surfaces, there would be a relatively small amount of virus spread at WDW. The spread would very likely be at a low enough level that anybody under age 65 and without a serious risk factor could visit WDW without having a significantly higher chance of dying as a result of the visit than the chance of dying from some other cause in the same period of time.
I fully expect the response that the small number of low risk people that get infected at WDW can then spread the virus to high risk people when they get home. First, the same low risk people can get infected at the grocery store. Second, if you can't stay away from high risk people for 14 days after returning from WDW then don't go to WDW. Let's not go to the "six degrees of separation scenario" of somebody getting infected at WDW because they came into contact with somebody from a different area from where they live and then returning to the area where they live and going grocery shopping and spreading it to somebody in the grocery store. Assuming there are social distancing and sanitary measures at the grocery store (or other location) in the home area, the prevalence of this type of spread due to visiting WDW is going to be very low.
Notice I didn't say that the risk is zero. I accept the fact that with WDW open there will be some number of people infected that wouldn't have been infected if it remained closed. I believe that if WDW opened with some modification to the operation, the benefits of both the enjoyment of the guests and employment of the CMs would FAR outweigh the detrimental effect of the unlucky people that end up with a serious illness or death due to WDW operating. People in the high risk groups can choose to stay away from WDW (or any other public place) to minimize the risk that they get sick although they should have the right to take the risk if they want to.
