A few thoughts on the 8/13 points.
Mangrum wrote: 1. Format: I rely heavily on published adventures as a GM, and I was always a bit sad that our reign coincided with the shunning of modules as a concept. I could not be happier that Paizo's kept the adventure path concept going strong, and so, as a GM, that's the route I would follow. After the basic setting sourcebooks, the focus would be on delivering information through adventure paths (linked adventures, aka prepackaged campaigns), with additional sourcebooks acting to supplement the adventures.
I’m also a fan of that way to do things. Paizo has an excellent way to do things, while putting mostly excellent source books out. I have a subscription on PF since the start and I use it a lot – adventures in part or in total, traps, NPCs, maps, sources and other ideas.
2. Timeline Agnostic: This is something the Kargatane were playing with when we were pondering making our own setting books just for our own use, following the Great Falling Out. I would lay out a history for the setting, but not necessarily declare that any particular point in the timeline is "now." Any of it could be "now," or at the very least, narrow "now" down to a single generation--say, 735 to 755 BC. Different adventure paths might bounce around in time. This isn't something I'd do with many settings, but Ravenloft is inherently static, in a fashion, because it's built so heavily on its characters. As the timeline advances, the "Graying of Ravenloft" inevitably rears its ugly head.
Exactly why IMC I started it in 748, to have a lot of future events I could plan with.
Think of it as a way to feature both Van Richten and the Weathermay-Foxgrove twins.
Couldn’t choose between the two so IMC again, the twins get adventuring sooner, so I have VR (semi retreat) and the twins adventuring at the same time.
3. Ravenloft is Artificial: (…) No more worrying about how a domain of X size can support Y large predators
Ah? This kind of questions were never that important for me, Ravenloft was something special where realism wasn’t to be expected everywhere. It never was a problem with my players.
Other domains, meanwhile, like Keening or Bluetspur, might have "blasted" ecologies, where not only is wildlife scarce, but fertility in general is lessened. Spells like plant growth might not work well there.
I might add other domain-wide attributes as well, like all enchantment magic being more powerful in Dementlieu, for example. Crafting poison might just be physically easier in Borca. Alterations to the planar fabric to enhance the themes the Dark Powers are exploring in that particular domain.
I like this idea. Interesting also as story hooks.
This would even extend to its mortal denizens. Natives of a domain just don't seem to be able to quite grasp the existence of the "glass walls" marking their existence. For example, there have been times when, woken suddenly from a deep sleep, I couldn't tell time for a few minutes. I could look at a clock, and I could tell that the numbers read "six-one-two," but I could not for the life of me put those numbers together to form "6:12." The same might apply in Lamordia--ask a villager for the year. "735 BC, naturally." How old is Dr. Mordenheim? "Oh, about 34, I think?" And when did he move into Schloss Mordenheim. "673 BC! 'Bout the time he got married, I think." So Dr. Mordenheim is 34... "Yes..." and he's been living up in that castle, a married man the whole time, for 42 years? "Yes? What are you trying to say?"
I’m not sure on this robot-like behavior, this might confuse players if they see it everywhere. Is it the normal people deluded or is it the darklord’s influence?
I agree all RL is somewhat artificial, but that is going a bit too far IMHO.
4. Ravenloft is Real: Once the Dark Powers create a domain, they keep it. The Demiplane of Dread slowly grows over the centuries, as the Dark Powers weave an entire world for themselves. Like the mortals the Dark Powers seemingly create, domains are effectively permanent fixtures, though they can change. If a darklord is slain, their domain never dissolves back into the mists. Killing a darklord, in other words, never ever means the end of the world for the denizens of that domain. Instead, the land is freed from its curse, for the time being. In the absence of a darklord, however, the unclaimed land becomes a yawning absence of power, just waiting to respond to the next damned soul to enter it. When the land does accept a new lord, it slowly and subtly changes to suit the new themes its darklord exemplifies--and the common folk can't quite remember that the natural world used to work slightly differently back in the day.
Interesting, no more cataclysms and misty voids when a darklord is dead. It’s better. More stable core, excellent.
Would it work too for Islands in the mists?
5. Heroes and Darklords are Enlightened: The defining nature of PCs in Ravenloft is that, for whatever reason, something has awoken them to the unnaturalness of the world. They are the handful of enlightened souls who can see past the limitations of their circumstances. Potential darklords are drawn from this same pool--they, too, are free to act as they wish, not at they must. Most NPCs, while fully fledged individuals, are ultimately trapped in the roles they were born to play.
Be careful not to make that too « normal » people artificial or theatrical. If the players always feel they are always in something similar to Juste’s plays, they will end not caring anymore?
6. Lighten Up: I'd abandon the pretense of Ravenloft being a particularly magic-poor world. It's not, and in practice it never really was. I'm not talking about adding magic item shops here; just an acknowledgement that yes, there's a fair amount of spellcasters running around, and and adventures in Ravenloft will include as much loot as they would in any other world.
Interesting. IMC I put magic as rare and its users often hiding. The main sources of spells for the PCs is a grimoire in the Weathermay family.
But I never refrain in putting magic in the hands of PC’s enemies! If they are defeated, they get the stuff!
In addition, I'd pull way, way back on modifying class abilities, spells, and so forth. Admittedly, this goes against bullet point 3 to an extent, so we're looking for a balance. I'd reduce Ravenloft's alterations to magic to a few basics (can't detect alignments, undead are resistant to necromancy, etc.) plus the basic additions of individual domains. Alterations to spells worked fine in 2E, when the spell pool was fairly limited, but in 3E we had to try to tackle the issue with a broad framework that just produced endless grief for poor ol' Ask Azalin. It's impossible to keep up with every intricate detail of the ever-expanding 3E/Pathfinder ruleset, so stop trying to fight the tide.
This never really was a problem IMC, and my players like the specificity and limits of magic in RL.
But that would possibly be a good way to have new players trying it.
It's Gothic Adventure! Go out there and stake some vampires, fall in love, and have some fun!
And, y'know, this would be as challenging as any other suggestion in this list, but I'd like to build romance into the setting as well. Sure, it's easy to say love conquers all, but let's throw some rules behind that!
Very interesting, for a Gothic theme.
7. Classic Monsters, New Approach: In 3E, we tried to keep the Van Richten guides as canonical as possible. This time around, I wouldn't really be at all concerned with what was said before -- this would be a fresh approach. I would present werebeasts, vampires, ghosts, and probably revenants too right off the bat as prestige classes, and encourage monstrous PCs fighting their inner darkness as a play style.
I see where you got this and where you are going with it. But I wouldn’t see a mismatch crew of monstrous newly created PCs walking the streets of any RL town. I don’t feel it, but perhaps as an option, I would have a player trying it (as he took the Moonchild PrC).
But sure, if a PC dies, this is a very cool option to have rules to have him back.
I would drop reality wrinkles entirely, not because I necessarily dislike the idea itself, but because I don't feel that years of increasingly fine-grained explanations about how they work ever stemmed the tide of confused gamers.

When you guys gathered here on Halloween, I nearly asked for a precison on reality wrinkles, as a joke ...
And as for the Vistani, while I accept them as a Gothic trope and don't feel any personal need to toss out the concept, so long as it's handled with a certain sense of cultural awareness and delicacy, real-world society's changed and there's a very vocal component of gamers out there who consider any form of "fantasy Roma" to be pure racism. I'm a little tired of fighting the fight on that one, so I'd probably follow WotC's lead of re-imagining the Vistani to make them more of a chosen culture rather than an ethnicity.
A chosen culture with magical powers? Could be a well defined class, like they tried to do in 2e?
8. Codify Darklords and Sinkholes:
Interesting ideas here, especially the lingering rage aura in a house where someone was killed for example. Fun. My players tinker with ethereal resonance once in a while, but that it could affect people too is fun.
I like the cleansing concept, it is fun. How it can give information on a darklord remains to be explained, but the concept has possibilities.
But the way to permanently dispel a darklord sinkholes require that you kill him. So it’s back to let’s kill darklords, instead of foiling their plans like we had in 3e. Mmm…
And why would anybody sane would clean the sinkhole of a powerful darklord (say Godefroi, Strahd’s or Azalin’s), if they were not 15th level? That often would be suicidal and the effect would anyway be temporary.
I think it is for the good of the setting to better explain / simplify the mechanic of becoming a darklord (or taking the place if the darklord of an area was defeated), for PCs and NPCs, but do we really need this as DMs? It doesn’t happen this often normally that there is a new darklord created. We use the darklords already in place much more often than create new ones.
I don’t know, I would perhaps eventually need to see an example to get convinced all the changes are worth it!
But the sinkholes “path” is really a fun idea.
"A full set of (game) rules is so massively complicated that the only time they were all bound together in a single volume, they underwent gravitational collapse and became a black hole" (Adams)