The reason that GTA:VC isn't as realistic as you would have wanted is because GTA:VC is a video game.
That's right.
GTA IV is now doing something different. It's gonna be MORE realistic, but some of these points will never be changed in the video game world like:
Also, why would you care about "putting on clothes in 2 seconds". Did you actually enjoy the fact that in GTA:SA you had to wait 10 secs to have CJ put on a shirt?
No. That's because it's not fun.
Also, would you like to actually punch a person hundreds of times to kill him/her?
The answer is no.