Hmm, sorry, UtM but I disagree with most of what you've said and would like to offer my own point of view on the races' age. It's easy to say that it's based on "facts" in the settings but I have yet to find any facts about some of the conclusions you've made.
For example, the Elves should have at least a 100 year life span, regardless of whether they are Dermorians or Nolthrir, simply based on the Elven traditional life span from various popular fantasy literature. That is if they're not slain in battle before that, being traditionally fragile and all.

I guess Ylians are comparable to real humans in their life span.
Lemurs and Kran were created by young and inexperienced gods, who did not listen to the warnings of other older and wiser gods, with Talad not even knowing about properly using the crystal to create life. So, it's very likely that those races would have many imperfections and not a very long life span.
Enkudikai should have significantly lower life span than humans being a feline(ish) race.
Your guess on dwarves was ok. Terry Pratchett's dwarves, for example, have a several hundred years life span, while some other settings state from around 100 to 120.
Klyros are a bit of a tough call. They are very fragile and were made even more fragile for passing through a portal,
"It seemed to suffer for passing through the portal...". But then it also says that they easily adapt to new environments. Elves are fragile too but are generally given a generous life span.
And now onto your conclusion about Diaboli, which I disagree with the most. Diaboli are pretty much demons or a demonic race, based on their name and description. In fact, the word "Diaboli" is mostly associated with the "Devil". Ever heard a phrase
"a demon's life span"? As in
"she seems to have a demon's life span" when talking about a famous person who's been alive for a very long time. Not only have Diaboli adapted to live in their harsh homeland environment, they are the only race that thinks of Yliakum as a real paradise (which means, all other races don't). They also have
"gorgeous, perfectly shaped bodies". While they may have good enough genetics to be inclined to such an appearance, it would take a great exercise and diet to keep in such a shape, since
"they have almost the same body proportions as humans, and almost identical internal organs". And healthy body usually equals a longer life span. Not to mention that
"The Diaboli developed a good resistance to many elemental spells thanks to a deep knowledge in that area of magic", which would translate into a good resistance against natural elements, those spells are based on, as well.
In fact, most demonic beings are either immortal or have a very long life span. Take a look at Warhammer universe, for example. Many demons have thousands of years life span and some are immortal. If even a human being decided to worship a Chaos god in Warhammer, their lifespan and abilities are enhanced by those gods' favors and mutations.
Ynnwn is self-explanatory based on what I've already said about Diaboli and Elves.
Just offering an opposing opinion here.
