Hmmm seems that you have played all your achievements against BOTs because you have got like 10 of your weapon achievements in 1hour. So no wonder you have so high KD >.< And i have to admit you're pretty fast to kill... 500-1000 kills in 1 minute with 98% accuracy.
No. I've never cheated on this account. Ever heard of a Achievement server? Played 5 hours on STEAM-GAMERS's Achievement server, that's why I got all the weapon achievements + kills that fast and that much.
The other achievements is mostly done with friends.