So I believe there's a minor issue with Ioun focus, maybe I'm just misreading or not catching everything. Ioun Focus grants the Ioun Kineticist the ability to take the Jagged Flesh wild talent as an aether talent. The only problem I'm running into is that Jagged Flesh requires Flesh of Stone, the earth defense talent, as a prerequisite. Nothing that I'm reading states that you ignore the prerequisite so it seems like you have expand into earth to take and use the talent. The talent seems very on theme for the archetype especially if the character works on implanting any ioun stones.
An ioun kineticist must choose aether as her elemental focus. She cannot select disintegrating infusion, foe throw, or force hook as infusions, nor can she select aether puppet, telekinetic finesse, telekinetic haul, or telekinetic invisibility as wild talents. She instead treats the following infusions and wild talents as though they were part of the aether element cyclone, fragmentation, jagged flesh, and rare metal infusion. These infusions can be applied to the ioun kineticist’s telekinetic blast and Azlanti composite blast (see below).
Source Occult Adventures pg. 25Element earth; Type utility (Sp); Level 3; Burn 1
Prerequisite flesh of stone
You painfully push forth jagged chunks of rock from your flesh. Until the next time your burn is removed, while your flesh of stone is active, any creature that strikes you with an unarmed strike or natural weapon or that grapples you takes 1d6 points of piercing damage. Weapons that strike you also take this damage, though the damage is unlikely to penetrate the weapon’s hardness.
"She instead treats the following infusions and wild talents as though they were part of the aether element "
I would take that as replace all mentions in the following infusions/wild Talents of "xxxx element" with "aether element".
It seems highly likely that this is RAI and to be honest it's also RAW for many users of english. That is, a grammer expert might disagree but more than a few people would write that and consider that they had actually said what we think they intended to say.
English is a sloppy language.
The thing is Steve the missing prereq isn't earth element or something, it's the specific defence talent 'flesh of stone'. I'd think it should be possible to use a wild talent specifically named in the archetype's class features, it's just that it's poorly phrased, but it's not a case of replacing earth with aether.