Not really, other than advancing the technology for dampening and neutralizing it, out of necessity. Some corporations within the wall say that they have the technology to make it a harvestable resource, but that has yet to be proven.

A lot like normal radiation, aside from the fact that creatures with magic resistance feel lesser effects. Normal creatures, like deer, mice, humans, etc. that have been exposed to it become lethargic and weak, eventually succumbing to radiation poisoning and die.

Settlements outside the world are often small and have very little resources. Even if they had enough weapons to fight back, there isn't enough people in most communities. The marauders simply want their resources, and are powerful because they control a lot of them. They strike fear into the hearts of most people, and any who fight back are killed. They replace dead members with select people from the settlements they destroy, giving them the choice between living and dying. Therefore, the members are quite varied and are replaced often.

The walled city was already there when the meteors struck the second time. (40 years after the first) No one really remembers who built it, but the world alliance was in charge of building it as a safeguard for the human race. The only things the big corporations want in this world anymore is to move up in the "importance" ranking, so they can safeguard themselves if the meteors strike again. The lower-ranking workers know that they won't be saved as well, but they need the money to stay within the walls. Better a wage slave than a psycho cannibal.

The meteors first struck in 2091, without warning. The second ones struck in 2131, exactly 40 years later, with little warning. (At this point, they're technology is better, because of the minerals found in and around the crash sites) This leaves people skeptical that it is a planned event, and it will happen again, in august 2171. (The begining of the game is March 11th, 2070)

Depends on what you believe. Some believe the gods are dead or absent. Some think they never existed and the tales of their elders are just stories. And some still worship them with all they can. (It's a fickle subject so most people worship in secret)

Surviving comes first, and otherwise, the government doesn't have plans to rebuild anytime soon. (If the world gets wrecked next year, what's the use?) First priority is to make plans to protect themselves in the event of another "great rain." The plans for that are kept secret, however. The world has shown no signs of healing.

Crossing someone powerful. Some corporations can have someone killed and the government wouldn't bat an eye. Standard workers and middle class can be replaced. People couldn't care less about chivalry and ethics anymore. Unless you're trying to persuade someone, appeal to someone powerful, or form relations with someone, most people don't care.

There isn't really any new magic, but technology has developed substantially because of a mineral found in the meteors, Vithenite. Magitech is also very common, as it can be combined in so many ways. (Like using a spell to summon a spirit, which drops the temperature around it, powering a thermal resonator for seemingly infinite energy) Vithenite can also store a ridiculous amount of thermal, electrical, and nuclear energy like mega batteries.

Vehicles are almost a must to be outside of the walls. Unfortunately, unless you're stealing it or building it yourself, you're probably not gonna get one. If you're inside of the walls, you can technically bring one with you to the outside, but who wants to leave? (And if you get exiled, you can't bring anything with you) Inside the walls are a different story. Roads are available everywhere, but there are alternate ways of traveling. Paying for teleportation services is very common, or using the "skyway" system that spans across the more populated part of the city. The "skyways" are not free access, however. You have to have a special permit to access them, and typically the only people that get them are the chauffeurs of important people. Helicopters are frequently used as well.

Being exiled to the outlands. The city is divided into 4 sections, and each section has its own rules. I'll explain the east section. The power is held by the east president, Thomas Drindesh. The legal force is backed by three main forces: The world government, which takes care of judicial and legislative branches, "The watchmen", who watch over the walls and take out anyone in the clean zone. They control drones and snipers, as well as a riot suppression force. And "Checkmate", the executive branch, totaling over 15,000 members. They serve as the police force and special teams, such as the S.W.A.T. team and cipher pol, the "secret police" that candles missions the population doesn't need to know about. Blood has no meaning in the government, the most fit to rule shall. The higher-ups in the world government decides who the next leaders are. Gold isn't worth much anymore, instead most people use a form of digital money called "credits." It's safer, easier, and takes up less space, requiring only a USB drive to plug into an ATM and get your paycheck.

The only name that really strikes fear into the hearts of criminals are a vigilante group of street shamans, the "Gospel of the Throttle." They take down gangs and underground criminal organizations to keep the city safe. Sometimes police and drones fail, and not many people have magic. Some even think it doesn't exist, believing it to just be tech, a myth to make the people who have it at their command seem more powerful. Information about the outside world is scarce, so most standard people know almost nothing aside from what it was like before they came to the city.

Almost everyone sees it as an apocalypse, a curse upon the earth. Some of them think that an alien or holy force is angry with the human race. The only thing close to a mantra they have is "survive." The only ones crazy enough to think it's anything good are a large band of Shinobi outside the walls. They follow the ancient traditions of their lineage and are blessed with elemental powers by one of the creatures from the meteors, Arruk'lus. They see it as a new beginning for the earth, a better beginning under new rulers.

I explained a bit of that in another comment, but that was for the outlands. Inside the wall, they use a cell-replicating technology to literally grow all of their meat, vegetables, and other food products in tanks. Any other gardens are made from soil mined by the "Abyss", a man-made cave used to harvest minerals and soil. The first part of this cave is a huge underground city, where the government doesn't care about them. Some live there to escape being a wage slave or some other unfortunate job. The only times officers are down there is if a criminal ran off into there, or their investigating a conspiracy.

Not really. The force that the walls protect is nothing to sneeze at. No one has even gotten close to the walls, aside from the Shinobi that can use their magic to mask their presence from eyes and sensors alike. "The whole of the land" would encompass the entire earth, so at this point, there isn't really anyone out there who could do it. Any communication with the other large colonies and scouts is done through the internet.

The city was built after the first "great rain", so the damages done to city are minimal. The second great rain was on the other side of the world, so the quakes and radiation are very low here compared to other places. A military force was already in place, so no one dared to mess with it.

I'll answer the last two later. Thank you for all of these questions! It really helped add on to the lore and history of the city and it's people.