Idea generation: What would the world look like if fungi took over?

I am working on a story about someone living in a world taken over by fungi, and I'm trying to generate some ideas. I've read/seen/heard that mycelium could actually be the dominant species on earth, fungi are older than animals, fungi have the potential to manipulate many things (as medicine, a drug, a parasite), and that fungi were the original plant roots. I'm reading a lot of books and have watched a few documentaries. But, I wanted to get some ideas about the following:

• How would a fungi takeover impact human religion?
• Let's say a disease took out most of the human population. What would an overgrowth of fungi do to the buildings?
• What are interesting ways that fungi could be used from a survivalist perspective?
• What type of fungi would be the biggest or most prominent?
• Are there any other interesting aspects I'm overlooking?