Since i'm new to the game myself and enjoyed
****ing around with the configs etc etc and watching like every video available on the matter of becoming a ''PRO'' or just not to suck, I also tried playing on 4:3 stretched.
For me it didnt work out although I can understand why some players do it.
I switched back to native now though. I do set my settings to low to get a constant capped 200 fps which seemed to help a lot hitting
**** wise.
Maybe it's just because things started to click after a lot of practice but actually managed to finish 1st on a server I played on where the players are actually proper quality. Maybe they just had an offday
If you havent done yet lower your dpi on mouse to 400 and then ingame sens to where you can play. It helps with accuracy a lot.
You might want to check this :
http://www.reddit.com/r/GlobalOffensive/comments/2ggkwt/csgo_optimiser_v_03b_patch_notes/
its quite handy to set up config and autoexec and startup commands.