The Nerve Gear has medicinal value for the terminally ill- it can slow the progress of some diseases by conserving energy, and they can experience things in the game that their illness prevents them from doing in real life.
This is actually a key plot point in Book 7 of the light novels, as Yuuki and the other Sleeping Knights are all hospitalized for various reasons—Yuuki is terminally ill with AIDS, for instance.
According to the novels, Asuna never had an interest in food in real life. So why did she become a master chef? Possibly because of the simple gesture of Kirito giving her cream for her bread.
Not only that, but she's grown up having food prepared for her; in Aincrad, she's preparing her own food. And as everyone who has ever cooked knows, there's a differences in satisfaction in eating something someone has made for you, and something you've made with your own hands.
There is a brief mention in the first volume about cooking in Aincrad not being as fun as real life, suggesting she might have cooked some in the real world. Considering the fact she does so at the end of the Fairy Dance arc this isn't impossible. This means there is another reason behind her mastering that skill; it was something familiar to her.
Alternatively she took up the skill because she wanted to find something she could relate to from the real world. Going off of the above, then naturally cooking would work for her.
The whole incident with the 75th Floor Boss is a deliberate echo of the Black Cats of the Full Moon, with Asuna representing all of Kirito's comrades.
Which is why Kirito loses his fighting spirit when he sees Asuna struck down. He loves her more than anything in either world, and the thing he most wanted to make sure never happened again happened again right in front of him, and again he was unable to do anything about it.
Since SAO lacked any sort of government, Kirito decided to become Sheriff. That's why he's called upon to investigate murders.
On that note, Sword Art Online invokes a Western trope of the sheriff confronting the corrupt mayor.
It's shown that Kirito has more sympathy for Kayaba than for Sugou, even though Kayaba harmed more people than Sugou did. The reason behind this is because Kayaba truly loved SAO and the VMMORPG genre and, while he indeed killed more than 4000 people, it was a restricted case; Sugou, on the other hand only saw ALO as a tool for his ambitions and vainglory and knew the implications and consequences of his experiments to the world if they were successful.
The second arc, particularly in the anime due to it being a more visual medium, has a huge spike in fanservice, with Gainaxing and Chainmail Bikini armour everywhere. In ALO. Which is run by Sugou, the creepy misogynist who sniffs comatose girls' hair. The fanservice spike is because he designed the game that way.
Leafa's reaction to Recon's Love Confession probably had something to do with the fact that he sounded like he was asking her to marry him out of the blue.
Kirito knows how the Nerve Gear works and how it interacts with the brain, yet is surprised to find that the revival item needs to be used within 10 seconds of death? Surely he'd know that after 6 months, reviving Sachi wouldn't exactly result in the same person he knew?
At several points doubts are raised as to the veracity of the death threat, particularly in the early months. Kirito's explanation for the ill mechanism was based on his knowledge of the Nerve Gear, but was impossible to confirm. That the players might suspend their reason in favor of a scrap of hope for some loophole, like "death" actually being a limbo state, isn't too far-fetched.