Unfortunately only way to get rid of the screen tearing is to use a graphics wrapper. You can find three options at: http://jkdf2.com/23-step-6-3d-acceleration-fixes-directx-wrappers-optional-depends-on-your-graphics-card-and-operating-system
, the one I use is DGVoodoo2
Also you most certainly need to limit your FPS to 47. If you go higher than that, the game runs at forced 30 fps. You can limit your framerate with nVidia Inspector, RivaTuner Statistics Server, DxTory etc. etc. It's up to you what you like to use.
I hope these tips help. You can find additional information from the stickied threads at the top of the page.
Strange GOG is selling this game in an unplayable state from the get go. This is not the GOG i usually adore and love. I thought only Steam sold games older games where the user have manage things by himself.