They only have parts of memories and the Erratic only remember tragedy anyway. He could have just thought he looked like an Anasurimbor but that doesn't make it so.

Erratics remember many mundane details.  Cleric provides clear evidence of this as he leads the scalpers through Cil Aujis.  They seek trauma to regain knowlege of themselves - who they were.  Those are the memories that can bind their fractured personalities.
But yeh, Nonmen can definately be mistaken.  But due to the identity of the nonman in question, there would be good reason for the face on his cloak to have been an Anasurimbor.

On topic, there is no reason to think Akka's dreams are true anyway.   There are two options imo.

If they are meant to precipitate something (which seems very likely) then something must be causing them. 
Moenghus sent dreams to dunyain @ Ishual, why shouldn't Khellus sends dreams to Akka? 

The other possibility is that Akka can access Seswatha's soul-memories (which are be 'stored' outside and accessed via the Grasping ritual).
Because Seswatha is actually Nau-Catyuti's father, Akka is able to access Nau's memories because of the ancestor relationship that most Earwan metaphysics alude to.  (I.e. the familial mini-dimensions that can intercede to save a soul.)
This (and Seswatha and Celmomas' estrangment) would explain the narrative necesity of including Seswatha's affair with the empress.

Either way there is the question of the timing of the dreams with actual events.  Does it seem like they are affecting the actions of Akka and thus affecting causality?

I feel that there is a chance that Ganrelka was Cel's first son - born of a teenage daliance and not originally expected to figure in the succession.

Kellhus didn't have any other breeding opportunities. Only Esmenet managed to produce (arguably) viable children for him.

Um, how many women did blind Moenghus/Mallahet the Priest have to choose from?  ...  Kellhus had a much broader range of breeding stock, imperial concubines are mentioned.  Like an empire worth of choices.  He has people who will conduct any secret mission and happily top themselves after doing whatever task he asks of them without question. Seriously ... he managed to find the only other worldborn woman able to bear dunyain children?

Maybe Esme was the only other one who could produce viable children (albiet with less success), but it wasn't for lack of opportunities.
Khellhus may have hidden offspring for all we know, seems more likely than Maitha having other secret siblings superior to Kellhus' gaggle of crazies.

Heh, similar line to my thoughts here, Locke.

Was thinking that by digging deep (kneeling in the deep caverns is holy according to Cleric) and creating a powerful topoi they displaced a piece of the outside that fell into a galaxy far away, a long time ago (remember that time flows differently in the outside).  Consequently the Inchoroi arrived to complete the task of inverting the heavens and the ground and thus seal the outside in.

What was the point of Cleric's third name? Incariol was the name he took as an Erratic Identity and Cleric is the name men gave him?

It might just be confirmation bias, but I felt like they were discernably different characters on my reread.  He doesn't choose different names - they are different people.  NG was the last king of nonmen, Incariol is an erratic and Cleric is the Skin-eater's pet quya.

But then his son, by some twist of fate (or divine interference), didn't die at the Tree like he was supposed to.

By the time of his death Moe has discovered nothing to contradict the Prime Assertion (TDTCB). 
Khellhus is the first thing to defy his conditioning, and even this can be attributed to TTT outgrowing it's inceptor.  For TTT's purpose, K is the only option, Maitha is dwarfed by a proper dunyain.

If Moe had time to secretly condition Maitha as a half dunyain, so did K. 
Perhaps K's children are more useful, stunted as they are and actually possess the same potential as Maitha. 
Perhaps they are purposefully limited by conditioning so they cannot oppose K.

Did someone say Contrarian Wanker?

I don't think its appropriate to use rape targets here. 
If you look in prison society you will see that male rape victims are also selected to a criteria of percieved weakness or vulnerability.  It's a predatory act.

In public, more culturally motivated displays of violence men will generally target other men - here it is a display of prowess and agression.
Can this be defined as male privilege?

Yep, damn patricians. 
Only rich folk had the right to vote in ancient Athens, for them it was one of those 'self evident' truths...  seems silly now but...

Abandon your convictions, Locke.
Its a debate from a different world, remember.    That said, I barely remember any of it its been so long...

Finished Planesrunner.  Didn't realise it was YA until I was two chapters in when it became very aparent from the predictable characterisation and plotting.
Doubt I will bother with the sequel, but not too bad if you're into that kind of thing.