Hmm, let me reply to Korittke, who, for some reason, utterly humiliated me TT, lol.
When I said shoot as his feet, it's done when you're at a little off close range, you know, the range when there's a knife fight. I should have said "Initially, aim for his chest but if he's too close and strafes (thus evades) then lower your aim as you shoot." It works for me because the bullets spray upward and in a T-like motion, and slows them down. Thus, spraying at his feet actually hits his chest and torso. I wouldn't suggest this if it doesn't work for me, and no the opponent was not a 'complete moron'.
About your second point, I should have clearly stated that you should stop after strafing left and right, as CuteGuy has. I didn't know about the shift though.
About the crouching, your point works (vertical recoil) and thus crouching is better. But sometimes, (when at very close range) crouching just lets them shoot your head. At a further distance, of course, crouching is better.
Also, I personally find jumping at close range to be effective, assuming my bullets count. I actually get lots of headshots with this, when I'm at a very close range (again the close range).
Finally, about the colt: that's just my mistake. I'm going to play without the silencer from now on. For some odd reason, I thought the effect was reverse... TT.