I would take kind of differing opinion about the relationship between the Warrens (including Elder ones), Holds, Houses and gods.
In short, new Ultimate Theory of Everything.
As there seem to be two conflicting chronologies, let's divide the problem into two planes.
First: matter (in other words - Wu reality) and spirit magic.
As we know from Wickan words - there was a time BEFORE of the Warrens (DG), where you found power inside. Quick Ben states in BH that this kind of magic reaches back to Eres - and it seems that their "mother", Eres is the eldest spirit on this world (Rhulad, MT).
Let's dwell on Eres topic a little: it is HER world. She is the fire that never dies (Ruin, MT). And all it seems she is also a sole origin of all human races (that is: the Eres, Imass and humans as known in modern days).
With Eres, there come the Wolves - Togg and Fanderay. The eldest companions, as they are described. And that forms the base of the most primordial pantheon, older even than Elder Gods in this world.
There is second base plane: idea (or magic)
As abstract ideas go, first there was Darkness (simply The Darkness, and NOT Kurald Galain), embodied by MD, and Chaos - everything possible, but without a direction or meaning (MoI). Inside the Darkness elemental forces [ideas] dwelled (BH), representing different faces of Order. As they are not only from this world (BH), they influence all the worlds in Malazan multiverse.
Inside the Darkness, Tiste Andii were created, and Deragoth come into beeing [best not to dwell how MD could have birthed the Dark Hounds].
And Mother Dark seeked something that is not defined inside her and hence Light has come into being (GotM), which brought angst and strife between Tiste Andii. With the creation of the Light, Father Light assumes/becomes bound to The Light, much like MD embodies The Darkness.
At about the time K'rul literally forges first two Elder Warrens out of Chaos (Starvald Demelain, the First Warren, the embodiment of change and variety) and Darkness (Kurald Galain - the Absolute Order, that was before the light)
Tiam assumes/is bound as an embodiment of change and power and K'rul is forever bound as an embodiment of Warrens (ways of magic), therefore the flow of magic is indeed the blood of K'rul. Out of Starvald Demelain there come the pure blooded Eleint, each aspected as a different kind of magic - and around their flight, Elder Warrens form.
The Shadow, Kurald Emurlahn is born among them , and I assume a specific deity assumes/is bound to concept of Shadow. (note: not Scabandari, as we know he came into power later and by regicide - slaying of the royal family [BH]).
The Elder Warrens encompass all aspects of the given issue (like KG - encompasses also the "darkness in the soul", or Tellan - "fire is life and life is fire"). It also means, Elder Warrens and their inhabitants are not pure ideas any more, but also have degraded into physical form. The classical Paths are more refined - they govern over a small fraction of the Elder Warrens' aspects, but are much easier to control and channel, allowing greater finesse.
At some point, as their physical aspect rises, Elder Warrens connect with the reality of Wu. And this infests both minds and bloods of the Founding Races with certain ideas (embodied by Tellan, in case of Imass...). It also opens a road to invasion - Deragoth are probably the most significant example of such intrusion.
I assume, that no Elder God (not Eres, Togg - these weren't EG) could stand on mortal grounds without becoming worshipped and known
as a certain personification of the idea, and spilling of blood is the offal to the EGs (MoI) because it forms a conduit between said god and reality.
As different shades of reality are linked, war is inevitable. As spilling of blood is such a strong conduit, a need for some moderation ensues. And so Errant comes into being and creates an order of Holds, where each Hold represents current contestants on the mortal ground (well, in a sense - there, where pure ideas are no more ideas but become physical manifestations). Current, which means that places in any given Hold are dynamic, and there is always some kind of power behind any given player holding a role.
And that is when Hood becomes Death (personification!). I stand that he is a Jaghut, as if Tellan encompasses life [GotM] - it's opposite (Omtose Phellack) should encompass death.
During the flow of time, both gods and mortal races evolve, growing to power, giving birth to champions (Ascendent ones among them) - and evolution of the Holds itself.
About 300 000 before Burn's sleep KE is Sundered, Tiste races invade and Ritual of Tellan is performed. The history begins.
Notes:
1) We don't know much about the origins of other Founding Races apart from the Imass - therefore I haven't yet fit their history into the timeliine.
2) Blood seems to be single most powerful item in the whole world - blood is a thoughest bind to break, it is simply liquid power
3) Otataral is a byproduct of magic use, if any powerful enough ritual is performed, otataral may form. (Heboric, HoC?).
4) Otataral Dragon is in my opinion a "erasure rubber" to destroy Warrens, if needed. Her name is uncertain.
5) Shapeshifting seems to be connected with some kind of a pact with the creature you shift into - for example, bonecasters seem to always have first part of their name fetched from the Imass word for the creature (compare: Hentos Ilm, Ay Estos, Olar Ethil), the Silverfox tatoo [GotM]
6) Sleeping with Tiam seems to be quite a popular way of becoming a shapeshifter

however the crucial part may be "the mixing of blood" [Osserc/Sisters dialogue, MT]
7) High Houses seem to be a refinement of Holds - changed and improved over the years, and not an alternative system.
8) Azath is not a prison per se, but a safekeeper (Paran/Draconus in MoI, Cotillion seems to imply something similar in BH) - an emergency vent, in case drastic changes are needed.
9) Warrens (at least their "physical" ends) are everywhere - and that means a wound of one Warren can influence others in the same "place" [that weird overlapping of warrens on Raraku Desert, a hole burned through "warren after warren" in Y'Ghatan (sp?)]