How was Mav1s able to show Joel images of his parents? How was the Mav1s unit seemingly so highly knowledgeable of the world and the creatures after the bugpocalypse when they were shut down for what was possibly years?
It's unclear how much technology progressed before the apocalypse, but it's not impossible that the internet was still up, and that Mav1s had the equivalent of 5G. Or that she had enough storage to contain a "snapshot" of certain portions of the internet.
What were the rockets that destroyed Agatha 616 using for propellant that the exhaust was mutagenic, and how does it affect such a diversity of animals (e.g. amphibians, crustaceans, insects, mollusks, etc.) but not humans or domestic dogs? Was it even the rocket chemicals/nuclear material or something inside Agatha? Was Agatha sent purposely to wipe out life and/or terraform the earth?
It's mentioned that only exothermic ("cold-blooded") animals were affected.
Which makes some sense...in a fiction logic sort of way. Cold-blooded animals can continue growing indefinitely as they age and get food, while warm-blooded animals stop when they're fully developed.
The first monster to break Joel's colony, why did it come? We are later told they are attracted to noise. Did the loud sex couple who liked to leave their door open accidentally entice the monsters to the colony?
How did the monsters exterminate most of humanity? They just seem like big animals. Scary, but not invincible even to ordinary people with crossbows. How are these creatures defeating humanity when they still had tanks and jets?
Answer: most of humanity is not trained to fight anything. In fact, most humans are trained to NOT fight, to buy their food from a store, and they would face some difficulty killing an animal for food even if they were starving. They rely on their militaries and police forces to do this sort of thing for them. The human soldiers were defeated (eventually - they are stated to have killed off the biggest monsters before that happened), leaving hapless civilian types to fend for themselves against billions of rapidly mutating bugs, slugs, and other creepy crawlies. It's not unreasonable that most people would not know how to find a bunker, not know how to fight monsters, and not realize how bad things were getting. Todd, notably, was eaten by his own pet goldfish!
Also, it was stated previously that there were creatures that withstood tanks. They and the military were wiped out together, which is why what remains are those killed by small arms.
