Questions on clean and unclean animals and how it affects Jewish life and conservation

Non Jew here, I want to ask some less talked about questions in a non-religious environment. So my next questions regard the topic of clean and unclean animals in the Torah. I am already inside many naturalist and reptile-related groups based in Israel, but I don't find the context to ask them.

So the Torah distinguishes between clean or kosher animals, which are permissible to eat and some are allowed for sacrifice, and unclean animals, which can't be eaten. However I noticed that there are various tiers of uncleanliness and not all unclean animals are equal. Large, herbivorous and useful animals such as horses and donkeys are esteemed and are just like livestock, minus the eating part, Large carnivorous mammals, pigs and birds of prey are somewhere in the middle and are doing their own business. Then there is a loose grouping of animals consisting of frogs, lizards, snakes, spiders, molluscs and so on that are called abominations and are considered the most unclean.

The first question is, do observant Jews kill unclean animals? I read for example that the Talmud condones the killing of snakes even in the Sabbath. Is it true? What about other unclean animals. Someone may not kill a lizard out in the field, but what about a house gecko or a frog in a sheep pond?

The second question is, how is daily uncleanliness dealt with? Although there is leniency for accidental consumption, many observant Jews still check vegetables for insects and thorrowly clean them. What about spontaneous situations in nature? If this is true, it means that children are disallowed from just eating strawberries or other fruit from the wild, which sounds cruel. Are other simple things, such as seashell collection, permitted? Also, how can children foster an appreciation of biodiversity and biology if all animal carcasses and parts are unclean?

The third question is, can Jews keep non kosher pets? Can you keep a pet snake for example? It needs to eat rodents, which are non-kosher or chicks, which may not have been killed the correct way. Even dogs and cats require meat, which may not be kosher, and cats may bring dead unclean animals in the house. Is a non-Jewish helper needed to care for them? Also, all animals eventually die. Are you disallowed from holding the body of a pet you have known for so long?

The fourth question is, is hunting and fishing even allowed? How can you hunt something if the only way of killing it is by kosher slaughter? Should you catch it alive and bring it to the shochet? Is hunting with trained animals also banned? How can you fish if bait like worms is unclean or you accidentally catch an unclean fish?

The fifth question is, are the Torah laws an impediment to some careers for an observant Jew? If so many animals are unclean, then professions such as biologist, zoologist, lab researcher, animal breeder, taxidermist, zookeeper, and even mundain ones like garbage collector are impossible for observant Jews. Do observant Jews even choose those professions? Do they need non-Jewish helpers? Still, many Jews are highly distinguished in careers such as biology and zoology. Did they encounter backlash from families and communities for choosing this path? Moreover, orthodox rabbi Natan Slifkin ammassed a large reptile collection,. How did he manage it?

The sixth question is, are those laws impacting conservation? Are those animals less conserved in the land of Israel compared to others? For example, the Nile crocodile, the European pond turtle and the Levantine viper got extinct in Israel, and the Nile softshell turtle got saved in the last minute. Could religion be a part of this, or is this too far-fetched? Are there any disagreements between conservation authorities and traditional Jewish communities on the issue?