Well, I've but dipped my eyeballs on but a trifle of things going on in here, but I've already had questions and thoughts bubble and froth to my forebrain that I'd like to posit within your midst (...midstes?):
1. What role does the internet play? I see there is mention of a Cyberspace plane, but what about computer access in other places? Are they like Astral conduits? Every computer can become a portal to Cyberspace. I suppose it depends on your "access points" where you can plug in? What about Wi-Fi?
2. Is there television and radio across the planes? How does one tune into them? What kinds of programs would there be on different planes and locations? Can one send foul or other magic across radio or tv? Televised sports?
3. How does cell phone use operate? Other telephone services? How would phone numbers work? Different area codes for different planes and layers and such?
4. Would the Hardheads now be the Flatfoots? Of course, that begs the question -- what of the alleged Faction War?
5. How does economy operate across the planes? Different currencies across different planes? How could one keep track of Limbo's economy!? Would it be similar to the stockmarket of earth, or something?
6. Are there grocery stores? Shopping malls? Hospitals? Parking lots? Subway systems?
7. What kinds of music might there be? Would heavy metal originate somewhere around the Lower Planes? Would bluegrass permeate the swampier areas of Elysium?
8. Would there be streets and traffic in (and out) of Sigil? Would dabus use their mind pictograms as traffic signals? ...nah to the last question
9. Would Factions be better seen as Unions? ...nah
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Here are some of my own meandering thoughts on some things. They aren't in any way detailed (yet), but may provide others with some mental sustenance -- err, food for thought.
1. Mechanus would likely be a world of circuits, powerlines, factories (entirely automated), and robotic or cybernetic organisms (mostly the modrons).
2. The (former) Sensates might now make use of their sensoriums and stones to create movie productions, creating new experiences from imagination.
3. I can imagine the Civic Festhall turning into a huge casino, surrounded by a very Las Vegas strip-like area.
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I'm sure more will bubble up. Feel free to toss out random bits yourself, or lend some flesh and bones to any of the above (or following) items.
Another possibility...
If there is television, there may be reality tv. What would the planar equivelant be to "The Amazing Race" or "Survivor?"