This is just frankly not true. There are an extensive number of arguments against eating even the eggs of adopted hens in your backyard. The least of which being you likely paid for the hen from a breeder that grinds up chicks like any other slaughterhouse.
To be honest a lot of this stuff is pretty easily answered and has been discussed ad nauseum in spaces like /r/vegan. This is also not a great space to ask this question of vegans, as a lot of carnists (yes that includes vegetarians) come here to argue against veganism and upvote answers they agree with but that practicing ethical vegans are likely to reject. You are likely to get better answers from vegans in other spaces.
In terms of your above post there is nothing scientific in what you’ve described. It appears you are using a veneer of science to avoid adopting views you disagree with. To be frank there is a lack of research on almost all animals in terms of their sentience, intelligence and capacity to suffer, presumably due to the carnist nature of society. There is also the unavoidable philosophical problem of other minds, which we are unlikely to be able to readily solve with science; we will never truly be able to determine the experience of another non-homo sapien creature and can only work through analogy to the experience of homo sapiens.
The above notwithstanding, even if some creatures are more “intelligent” in some ways than other creatures, how does this impact their entitlement to the bare minimum of moral consideration, i.e. freedom from intentional harm and exploitation? How have you determined that each “tier” that you have created only deserves the rights you have designated? The assignment and exclusion of moral consideration is the province of philosophy and politics, not science. There are certain classes of humans who are alive, and through severe disability or illness, have intelligence arguably lesser than many of the animals listed above in your lower tiers. Would you therefore exclude them from moral consideration? Of course not, and this is why intelligence is irrelevant to moral consideration - it is not a morally relevant characteristic.
The morally relevant characteristic that stands philosophical rigour to determine if moral consideration should be granted is a capacity to suffer. It is pretty clear that all of the animals listed, apart perhaps from tier 5, have this, so it makes sense for these animals to have moral consideration.
You have also completely ignored the well established link between commodification and carnism in the above, which is a key reason, as to why exploitation and commodification of animals is ethically unacceptable and should be eschewed - the commodification of animals, or relegation of them to zoe, is fundamentally how we as a society and as individuals justify their ongoing torture, mistreatment and slaughter in most ways throughout society. This is without even going into other issues regarding exploitation, such as an inability for an animal to provide meaningful consent, and respect for bodily autonomy that we grant other individuals, regardless of intelligence.
This doesn’t mean that vegans would generally be opposed to adopting animals to care for them, or opening sanctuaries - most people I have encountered and literature I have read understand that we operate within the internal logic of a carnist society, and that while it is unethical to engage in the support of further breeding, it is ethical to care for adopted animals (or animals you had prior to going vegan) that have already been brought into existence through this system.
In terms of your tier 5, due to the lack of research here, the problem of other minds, and the lack of necessity here for people to engage in the exploitation or harm of these creatures, I am of the view that the default position should be erring on the side of caution.
If so, I use it because it offers unrivalled flexibility, even compared to Arch, portage, which is an epic package manager, a dedicated security team, reasonably large community and developer base, source-based package distribution and fast package updates, which often outpace even arch.
Phoronix has always had a strong editorial bias. No mention that Firefox has recently caught up on Speedometer 3 or the other benchmarks Firefox is faster than Chrome in.