Thanks for the quick critque, I'll put in my answers to the few questions in Red, and will work them into the main post later. I will address the non-question issues later when I get more time.
Quote Originally Posted by JCjr View Post
Given the amount of material you've set out, I think it'll be easier if I just give you feedback in point form.

First off, I quite like the notion of the sentient Prime races teaming up to beat up the whole Pantheon - 'good' and 'evil'-aligned clerics and paladins (or blackguards) would be a the core of the world's forces as their magic and powers are particularly effective in permanently taking out demonic or angelic entities.

Second, you might consider coming up with some shorthand for your calendar, i.e. some way for more common folk to keep track of the days and months as your formal system produces rather lengthy and complicated dates.
Good point I'll start working on that.
Third, how would the diplomat status of the head of the Steamforged Knights play out given that they are based in Terrantis and that the status only applies there. Does it provide the head with some sort of immunity from prosecution? Is the property of the Steamforged Knights not subject to Terrantis' laws?
The Steamforged Knights were a relatively new addition to the setting (I actually added it in to accommodate one of my player's character concepts. The idea is that Terrantis, and Terrantis alones, treats the property of the Steamforged Knights as being its own nation. That does mean the head of the order is immune from prosecution from the law, and those who stay in the Steamforged Knights are considered foreign citizens, exempt from taxes, but can be punished by the letter of the law as if they were foreigners. Buildings owned by the Steamforged Knights are considered not the property of Terrantis and follows its own laws. However officially speaking, none of the other countries recognize the legitimacy of the Steamforged Knights as their own country, because strictly speaking they have no real continuous territory, but a few buildings owned by the organization.
Fourth, I love to hear more about the unknown entity that murders anyone entering Umbarius, though keep some of the vagueness. Particularly, how precisely did the wizards figure out to protect against it? Camouflage or a more straightforward shield? Could the protection be related to something particular to that entity?
Simply put, the creature is really unknown, because literally has survived an encounter with it, the reason why the spells that travel through this plane works is simply put, it doesn't let the caster stay there long enough to be hunted down. It takes at least a day for the creatures to hunt down intruders on the plane.

Seventh, please expand on Necros - it sounds really, really cool and the consequences that this all would have for a society are mind-boggling. What position would more sentient undead have and is there some way for ordinary undead to ascend after their term of post-humous servitude has run out? Are zombies perhaps modified to make them more suitable for their particular tasks, e.g. an implanted lantern in a zombie's chest for guides or added muscles to make them better dockworkers?
While I'm sure some of the people who make money off of animation of undead do make some modifications (such a precedent could be found in feats like Corpsecrafter which would still be available in game) but a larger part of the market is finding the right natural corpse for the job. Mindless undead are basically treated as guilt-free slaves, there really wouldn't be an easy legal way for them to ascend to sentience besides something like Awaken Undead. If a zombie or skeleton were to gain sentience, it would also gain full citizenship. Sentient Undead are considered only slightly below the fully living if not equal. They are able to run for office if they wish, and some are quite affluent on the island. The Archmage of the island himself is publicly a lich, having been one of the original Archmages.
Eighth, where does water and food come from? Do they siphon water up from lakes or collect rainwater? If its the latter, the islands would be particularly disliked by those stuck on the ground as a lack of rain could lead to draughts, in addition with the large shadow the island itself would cast over the land. Are there special farm islands? What about animals and other needed resources like wood or stone?

To be honest I felt it entirely possible for the islands to rely on importation of foods from the lands below. If you would take into account actual size, the floating islands are actually much smaller than any of the lands below. Verdantis could probably afford to export food to the islands and still feed its own populace. While the majority of the Floating Isles water supply comes from rain water, they are able to reuse a lot of it, through a filtration system, as well as supplementing it with the Cleric cantrip Create Water(Although obviously not to the scale then say the Tippyverse does." The islands do move quite a bit, as they aren't precisely anchored to anything, preventing them from stealing "too much" rainwater from a region, as well as not casting a huge shadow over an area. The Floating Islands would be perfectly happy to trade simple magic items to the lands below for natural resources, and with The Floating Islands having a much more highly concentrated arcanist population, they can do so at a rate much larger than any individual nation below.