ES is for all intents and purposes non-cannon, but some elements from it are 1:1 repurposed or translated, right?

EL and DotE are cannon, the same goes obviously for ES2. The Last Flight as well.

DoTE and Quest in ES2 mentions Success, a Mezari Penal Ship, possibly a Colonizer, with a population of

that most likely hugely deteriorated by the time of landfall of droppods. Only drop-pods survived as the ship was DESTROYED in space, and completely torn to shreds. This is also a ship that had Opbot as a prisoner (probably) [there seems to be some confusion] yet he still was a passenger of that ship.

EL has Mezari, security detail, virtually a swap of Vaulter faction, save the lore of few heroes. They seem to be their Ancestors, and there seem to be more than a few to let themselves experiment on the whole bunch of people and consider them rejects. Also, they seem to came on Auriga on Argossy, which seem to be of high-tech, with portals, unknown to Endless, as it seems with unique outer-ring construction OR on a different ship earlier. My money is on Argossy.  (this crew also seems to also be ancestors of at least Forgotten, possibly also Sisters of Mercy and other humans of Auriga. Argossy survives more or less in one place.

The mentioning of convicts as an only source of Ancestors of Aurigans/Vaulters was quite straight wrong. 

Why?

Because in DotE there are already Sister(s) and Broken Lord(s). Those lords are of uncertain heritage - post-Roving Clans humans, post -Concretes? There are also Delvers, that seem TO BE post-Concretes.

Raia Dilemma:

There we also have the Last Flight of the Grey Owl, which discusses, sometimes on the verge of breaking lore, that Raia (which was settled post Mezan, the home of Mezari) was already settled all those thousands of years ago by humans, yet in ES2 it was settled by Mezari, then apparently forgotten all high science, THEN composed Raian persona(while semi-foregoing Mezari heritage) and finally emerged few decades before ES2 timeframe as a spacefaring empire. btw it also mentions Hissho having noses and Haroshem having ONE eye [how us what's behind those masks!!! ] while also making Golden Age Torians less of a gods, and more like humanoids, yet different from Raians. This doesnt explicibly state they were alien(like in ES). 

Lots of confusion.

So - who's in the wrong here? Why its Raians and not Mezari? What is missing?

Im asking this, as I sense, that Mezan will play a role in the future, with Isyander looking eagerly for Mezan, a barren world, but filled with Endless and possibly pre-Endless ruins. He doesnt seem to be looking for Tor or Bilgeli so frantically. 

The origins of The Engineer Hero and the Riftborn (possibly the Grim Reaper too?) suggest that Auriga might actually be a weak spot where other worlds can more easily bleed into the one ruled by Dust.

From what I gather from these is that:

BLords(and their cousins)and Delvers are offshoots of Concretes who survived the Dust Wars. While the first ones eventually emerged, the second ones dig deep, deeper than Vaulters after for a far longer. Their survival, as they claim, is thanks to the Dust. They seem to be normal sized(eith strangely one art showing dwarves) and in a ritual scar their faces and wear skulls as masks. It's very important for them. Haunts are probably footsoldiers of Virtuals caught in their own bombardment.

Notice that they all wear masks and survive using Dust. 

BL pre-spiritification also covered their faces, even their civilians and women, evolved into Roving clans, these evolved into Ardent Mages and Dorghesi(that wear masks)(probably split shortly after the first break). Sisters of Mercy are "a recent" offshot of humans but must be at least as old as Vaulters, as they appear in DotE. At the time of DotE BL might not be confined to their suits for all eternity, but it's after the split with the Rovers.

Then there are humanoids like Wild Wakers, that might be mutated humans - yet it's pure speculation.

Vaulters (Mezari) are quite a recent addition, prisoners and crew of Success, Forgotten their experimented upon brethren.

So there's another question - Argossy. It's old, post-Dust Wars, it's Mezari like Success, but not Success. It probably was also shot down by defence sats. It has hyper-advanced technology, that is advanced even in ES2. 

Who came with Argossy? What happened to them.

EL pretty much confirms Endless(Torians) = Humans. Yet Last flight qualifies Torians as different from "Raians"(humans)...at least in name. Yet Raians are said to be Mezari (from Mezan) colonists...and only after some time used this name. Yet Mezan is something different from Tor. Where are lore creators, where is the word of god?