Nah they aren't demi gods nor divine. Pretty similar to how siris is created from something divine but isn't divine itself.
This is important to note because in the NW, this does not mean Atavistic Flames or GST will do extra damage or have unique interactions with Arali; while formed from Divinity, they are not actual Divine beings. Keep this in mind.
If 40 Siris meets 70 chakra sealing technique, it'll take 4 turns to decay the seal or container.
If it is forced into someone, I'll assume it'll effect ppl how I described it effecting "live container" that absorb it. Damage them turn by turn with the decaying effect. Think it's 20 damage per turn for every 20 chakra in the technique. So a technique with 40 chakra is inserted directly into a person would do 20 damage over 3 turns? Or does the damage go up, doing 40/60 damage per turn?
This is something I have to make sure is fully understood because it forms the bulk of most interactions based on absorption with Demonology techniques. As you correctly stated, 40 Siris meeting a 70 Chakra seal would be absorbed and after 3 additional turns, it would release. An easy visual guide is:
If Siris and Chakra is equal OR Chakra surpasses Siri by less than 10 = Jutsu releases after ONE turn
If Chakra surpasses Siris by 10 = Jutsu releases after TWO turns.
If Chakra surpasses Siris by 20 = Jutsu releases after THREE turns.
Etc.
While this is just repeating what you said as well as what’s in the threads, I wanted to include the above bit for anyone stalking since people dont like to read rules and pretend things aren’t there (I’m looking at you, Venom).
When it comes to different arali and how/why they differ; I would assume because it's like having different races of the same species like humans have. Like a human could be a normal human, an Uchiha or a hyuga: All human but with different abilities. In the Case of Arali, they have 4 classes or races. These are Asag, Sulpae, Lilin, and Utukku.
Asag are I guess the more common and low class of Arali. Being kind of like earthy in skin and hard by nature. They even come with 3 or 4 arms sometimes and are seen as "stonemen" as a whole. With this in mind, they spec in earth techniques and taijutsu since they are underwhelming Siris wise.
Sulpae on the other hand would be the more angelic arali if we look at Asag as demons. They are usually very petite in body build and are seen as beautiful amongst their peers and others. Overall they're great healers and have optimized the fields that have healing in it. So medjutsu, specific arali techniques and yang.
Then there's Lilin master race. Lilin are also seen as demons and don't have a true form; being able to shapeshift at will and take on basically any form they choose. They specialize in spiritual abilities.
Then there's Utukku. These are the rare breeds of Arali and are monstrous in appearance, even compared to the Asag. They have bluish green feathers on their body, claws and grotesque looks. They deal in sound and suppression abilities that are said to be the strongest of Arali skills.
Arali can have advanced elements and hidden abilities. They can't have kg, nor modes that deal with humanity or senjutsu.
This one is a bit more complicated to answer fully. You have the how part down, but not the why. This goes more into lore and theorycrafting so we leave the firm foundations of rules to go into the realm of theories. The Arali were created by the deities for various reasons but all for specific purposes. Looking back at the Irkallan raid, there were several Arali there with different tasks - the Gallu, the various thrawls, etc. These “demons” were created to help guide the souls of the dead to Falnir for judgment. In Eanna, there are several “angels” of Anu and others for various purposes. There are countless Arali types — many of which are still hidden and yet to be seen. When the Cataclysm happened, several of these demons fell to earth and made it their home though a majority still reside in Eanna or Irkalla. Of the ones that landed, we have the Lilin, Sulpae, Asag and Utukku. Each of these have different original functions in Eanna/Irkalla that they no longer carry out on Earth such as the Utukku being used to help fight off the Lahmu.
Tl;Dr Arali are different because of the tasks the pantheon set for them with some assisting in helping the dead find their final resting places, helping others find comfort in their deaths and more. When they fell (or rose) to earth, they took their innate skills and tuned them for other purposes, leading to many learning ninja skills and here we are.
We have covered a majority of the background information. From here, we move on to techniques. BEFORE that, is there any questions you have regarding Arali rules, restrictions, and anything else that isn’t related to the techniques?