So, little update on my experiences.
I tried the no aero thing, and while it made kokiri more smooth (i'm pretty sure) and maybe with less color distortions it seems, it made the Helix rollercoaster a judder hell. I hope all those things will be fixed shortly and we'll laugh about them!
I wanted to find a way to at least, for a beginning, see my 3D wallpapers in the rift, as static picture. it was a long process to find how..
First, to find a way to have the proper barrel distortion. In the end i'm using
Stereoscopic player which is not free but there is a trial limited in video time. And you can use it with pictures, side by side or others. I just had to use StereoPhoto maker to split my mpo. Then i just print screen on the result distorted sidebyside, and here we go.
Now to quickly and easily see a fullscreen 3D picture on the rift, i use irfanview.
_I put the rift in extended mode (on the rift manager and on the dektop options), not primary!
_Then it's to have it fullscreen, and work also with videos directly on StereoPhoto (but irfanview is less a pain in the ass for pictures): Put the window on the other side, oculus part of the desktop. Now when the rift enable, you won't see irfanview anymore, but it's ok. You can still select it in the task bar and if you open a photo, just click enter for full screen, then put the rift on (i don't use the straps when just seeing a pic, i just look into it.
If people want to try, it's easy (probably many of you already knew how to do that anyway

)
Here is the
zip with many pics anyway, if you want to see some rare exemple of 3D digi painting with more than 50 layers of depth.
I would advice the Batman one, which is mind blowing. That scale and depth o m g. Try it. The Sonic and Pokemon one works super well to.
And i want to add those are great exemples of how an advanced 2D game could work with the rift. And it illustrates something i wanted to believe theoretically:
Certain game will benefit from a frontal experience. Look at my pics and imagine a simple 2D game, projected on a vr screen (like the vr cinema), with a big fov (not too far away), and it would just be like a window, with the perspective changing when you move your head. Every 2D game is possible like that, as long as you don't put any gameplay on the side lol.
Next step for me is to find a way to try that with Unity and my screens, just being able to look into it with 3D layers on a 3D plane.
I hope it was interesting to someone