I'm always playing Windowed Mode so I tried fullscreen instead : Same result.
I did set all the graphic options to "Low" in case of, even if my FPS are good.
My keyboard is wired, and got no special maccro buttons or anything, just a normal keyboard
I've tried moving the keyboard repeat rate to minimum, maximum, and middle; same result.
That said, thanks for helping me but after googling "skyrim 3rd person delay" I saw a mountain of people talking about the same problem I have... The most common answer is "This is how the 3rd person works, the delay is intentional so your character look "less stupid" moving around."
That makes sense but you guys seems to not have these 0.5s I'm talking about so I'm confused :$
PS : I've tried a bit of everything, turning on/off Vsync., disabling some keyboard options (sticky keys etc.), deleting all my mods, reinstalling the game..
PPS : I have no problems at all with my mouse, aiming is totally fine.