I don't know if i'm missing something, But i've played with silent patch and the aiming is fixed there, I understand that's not allowed for RTA so i've been trying without any silentpatch. AND it's borderline impossible for me to aim, No matter how low i make my sensitivity while aiming the vertical sens alone is insanely fast, while the horizontal sens is normal, it's extremely jarring and feels unplayable, how do the really good speedrunners deal with this?

If you change the in-game sens it will screw up vertical sensitivity, put it as default and change your mouse DPI to a low one e.g like 850 (what I use), You can use Dinput.dll to fix the aiming.

thanks homie. I just changed my dpi and adjusted the ingame sense and it feels much better now.