The only way I can get error 90000,constantly, is by reaching around the back of the PC and unplugging the ethernet cable. Error 90000 after exactly 30 seconds. I otherwise never see it, and this is the only game that ties up one CPU core. Aion by comparison ties up half a CPU core. If I select "Maximum settings" in graphics, the CPU usage goes up to 25%. In a crowded area. If I turn every setting off... it goes up to 30%.
(This is on a hyperthreaded quadcore, so 30% = 2 physical cores or so.)
I can only make it drop to 12.5% if I lock the frame rate to 30fps. Changing the screen resolution or any of the other settings has no bearing on the CPU. So as CPU heavy as the game is, it's certainly incapable of using more than 2 cores, and most of the time only uses one. That is likely in keeping with how the PS3 version works, since the PS3 only has one core, and 8 special purpose-not-quite-a-CPU parts. Why make it more complicated. If and when we get a DX11 version (and hopefully 64bit, did you know Aion is 64bit and uses more than 4GB of ram? FFXIV is 32bit and peaks around 1.5GB) that should allow the game to load and keep more assets in memory, and drive down latency caused by loading. There is way too much loading time in this game.
Back to the topic itself though, compared to V1 launch, this is a drop in the bucket. The V1 launch, SE completely ignored beta tester feedback, launched a copy-paste scenery that made the game look rushed, and had lots of places to wander into and die in one hit. It had the hallmarks of being rushed, or outsourced. V2 the game actually works at launch despite some launch issues, and the people complaining the loudest seem to mostly be people with high-end rigs that.... I don't know... maybe they're too fast for the game and it overloads their network.
Anyhow. People aren't using the search button. 90000 error problem is specificly network related, mostly on the end-user's end. If players are not willing to plug their PC directly into the cable modem and check of the problem persists there, then they are going to have to suck it up and suffer.
This is not a "set bugs=false" flag somewhere for SE.