Actually I think the numbers are comparable.
The WHO issued a statement (August 2024) that ~175k people die per year in Europe due to heat (between 2000-2019, statement with source, based off a 2021 study, for reference, they also estimate ~660k cold-related deaths per year).
For other studies, we have two from Nature (2023, summer 2022), which give estimates of ~50k and ~60k heat-related deaths (I assume most heat related deaths take place during the summer). The Lancet has a study (2024) that finds that between 1991 and 2020, there was a median of ~40k heat-related deaths (and ~360k cold-related deaths) per year.
For gun deaths, the CDC (via Pew) states ~45k gun-related deaths in the USA in 2023, so a comparable number, although slightly less.
Of course, Europe has about twice the population as the USA, so one should make per capita adjustments accordingly.
You cannot completely understand the immune system; that is something you learn early on in immunology.
That being said, the key understanding on mirror bacteria evading the immune system is that the immune system generally relies on binding to identify foreign invaders, and if they cannot bind then they cannot respond. Bacteria generally share a number of molecules on their surface, so the innate immune system has evolved to bind and detect these molecules. If they were mirrored, they would not bind as well, and would be harder to detect and respond to.
That being said, you did find the insight that they are not completely invisible. There are also systems that can detect the damage done by the infection and start a counterattack, even if they can't see the invaders themselves. But much of the counterattack would not be able to affect the mirror bacteria.
What matters in the report is that the immune system of all animals and plants will likely be (much) less effective against mirror bacteria. This doesn't mean it's an untreatable disease, as we have antibiotics that should still be effective against the mirror bacteria. But it does mean that if the mirror bacteria finds its way into the environment it is unlikely that anything can fight back well.
I work with bacterial viruses in liquids, and when we want to separate the bacteria from their viruses, we pass the liquid through a 0.22um filter. A quick search shows that the bacteria I work with are usually 0.5um in diameter, whereas the smallest bacteria can be down to 0.13um in diameter; however, the 0.22um filter is fairly standard for laboratory sterilization so I assume smaller bacteria are relatively rare. The 0.22um filter can also be used for gases.
But as with my usage, they block bacteria and not viruses. I'm working with 50nm-diameter viruses, but viruses of bacteria are generally smaller than those of animals; SARS-CoV2 is somewhere from 50-140nm.
If you use a small enough filter it would still filter out the viruses; but you'll need to get a pore size smaller than what is sufficient for filtering out bacteria. (and smaller pores requires more pressure, more prone to clogging, etc.)
(though for air, it's quite rare for bare viruses to be floating around; they're usually in aerosols (bacteria are often also in aerosols, which may be easier to filter out)
I think focusing framing against mirror bacteria is harmful for the project, as opposed framing it as protection against any general (synthetic) biology risk. Or even colonization of an alien biosphere.
There are a few classes of commonly-used antibiotics that are achiral and would still work against mirror bacteria (trimethoprim, sulfa drugs). We lose the most commonly used ones, but any human infection could probably be treated with these achiral antibiotics, especially since the growth of mirror bacteria is likely slow due only being able to utilize a small fraction of resources. They could evolve resistance, but they would lack access to horizontal gene transfer from non-mirror bacteria, requiring any resistance mechanisms to evolve de novo.
The main threat of mirror bacteria isn't direct infection of humans, but how they could reshape the biosphere and impact food security, which hiding in a shelter does not protect you from. Other, more targeted risks, such as bioweapons, pandemics and viral outbreaks would be better served by these shelters (though I'm unsure if your filtration system is designed for viruses).
Nitpicking at the example, worker bees do not have offspring; the best way for them to spread their genes is to protect the queen and thus, the hive.
Birds can have offspring, so self-preservation instead of risky attacks is optimal for individuals of a flock (of genetically unrelated individuals).
It's not that the group is less intelligent, rather that the individuals of the group have different goals (self-preservation vs hive preservation, though the end goal of maximizing fitness is the same).
But genetic fitness breaks down as a metric when you add culture to the system, so application to humans is limited.
It is important to note that people have a wide range of attachment to their gender identity, ranging from willing to undergo extreme body modification in order to match their gender identity, to those who don't care in the slightest.
The issue is that cisgender is the default, and if you don't have a strong attachment to your gender identity, you have no reason to change the label. Hence, cisgendered people have a wide range of attachment to their gender identity, from strongly identifying with it to no attachment at all.
(There is also the group of agender, which includes those who have deeply examined their gender identity and decided that they don't really care (and probably also want to signal their examination and non-caring of gender identity))
Someone who is transgender obviously has an attachment to their gender identity, and this is obviously from which the Pronoun Discourse stems. They have a strong preference for a gender, and a preference to be referred to with the appropriate pronouns, and thus being misgendered is upsetting, as their preferences are violated.
(Of course, most of this rests on the ability to communicate the preference, and accidental violations when the preference was not communicated are less egregious than deliberate violations.)
Otherwise misgendering can be upsetting if it is tied to stereotypes of masculinity and femininity and attempting an insult based off those stereotypes.
Incarceration plays three roles (to varying degrees of success): punishment (and therefore deterrent), rehabilitation and exclusion from society.
One group of people would prefer focusing on rehabilitation rather than punishment, and are likely those who oppose solely serving vegan food to prisoners. Another group of people sees prisoners as no longer human and deserving of moral concern, and think that the cruelty of prison is the point.
The US prison system leans more towards the latter than the former (see: mandatory prison labor), though other places in the world lean differently. How far and in what direction prison systems should lean is a topic for philosophical debate.
Though also note that degree of punishment doesn't really correlate with deterrence from crime (review Apel and Nagin (2011), tl;dr: more about certainty of getting caught, it's complicated)
I have issues with this: I don't think you can claim that wildcats of the stone age would be pleased with what we've done to domestic cats either, sticking them in tiny territories where they cannot roam, kingdoms of a cage. I'm not sure using human judgement in this matter is very useful as we don't have a good concept of what other species value.
I don't think evolutionary pressure is an intelligence; it's in the name. It's a pressure, like air pressure or water pressure, not an intelligence. There is no agency. The end results can be marvelous all the same. Evolution appears to make FDT-style trades, but is actually completely myopic. It's survival of the survivors. If you're dead, we don't see you.
Also sociality in spiders has evolved independently at least twenty times, and keeps going extinct. It's probably an evolutionary dead end due to inbreeding [1]. Evolution is completely myopic.
We do, however, build rooms full of cats and catnip.