Another aspect of Daki fan fiction could be the alternate universes. What if Daki was never a demon? How would her life be? These are the kinds of creative ideas that can be explored in fan fictions, and they often attract fans who want to see different interpretations of the character.
One popular theme is redemption. Since Daki is a demon, some fan fictions might explore the idea of her finding a way to redeem herself. This could involve her making amends for the harm she has caused to humans.
Maybe. There are many works with similar names, and some might be comics while others not. You'd need to provide more information to determine for sure.
Tanjiro might use his sense of smell to detect hidden threats. Since his sense of smell is super - enhanced, he could sniff out any demons or traps in the way of saving Rengoku. For example, if there are demons disguised as allies, Tanjiro would be able to tell by their scent.
Well, in a comic, it might be shown as some sort of fantasy or humorous scene, but in reality, kissing a lizard is not a common or advisable thing to do. So, it's hard to say exactly how it would be depicted.