You see, Counterstrike is a very old game using the OpenGL API, which basically means that NEW hardware and NEW drivers may not emulate the right way the cs graphic engine.
Downgrade your graphic's drivers. Install an older version and see what happens.
*You can also try changing the video mode, from OpenGL to D3D.*
The thing you mention about your mouse, it's vertical's sync side-effect. Be sure you disabled it. It's tricky sometimes. The game looks prettier because of the Frame-Hz syncronization. Vertical Sync sychronizes the data between FPS and HZ, to make it more smooth and prettier as you say.
Vertical sync is a MUST while playing a Direct3D based game.
ako ti ne radi taj driver dobro idi na desktop --> screen resolution --> advanced settings --> adapter --> properties --> driver --> roll back driver da ti automatski vrati na prethodni driver