The mouse actually seems somewhat non-time scaled. It screams 'templates' with the sound effects and weapons behaviour, so I would think it would be properly scaled... Might want to take a peek though- every time I play a templates-based game this is the case with the mouse.
Otherwise, drop sensitivity just a *tad*.
Game speed is also a bit fast in my opinion. And I swear that bot moves faster than me... might be time-correction? He can also aim much faster than the mouse allows, meaning he can grab a gun one second and be shooting me the next without the time to turn around.
Jumping would help a whole lot too I got killed probably 5 times because I thought I could jump around to avoid his shots only to remember my feet were glued to the ground. I was toast.