First off, in my opinion you are better off running a different linux distro on your laptop and just installing the tools you need. Kali isn't really meant to be ran as a main OS (but its a hell of a lot better than backtrack)
cat /proc/asound/modules to see which alsa modules you have loaded. in a lot of cases alsa has just chosen the wrong default device, and you may need to make an .asoundrc to fix it.
for your video drivers situation, it looks like that laptop has an optimus setup (two video cards) the last time i tried to do this it was hell, but luckily there has been a lot of progress in getting optimus cards working in a linux setup. you might try following this guide i found for setting it up on kali: here
Bumblebee works by running your intel card for most applications but you can run certain apps using the nvidia card with a simple command, its the preferred method of getting this work because your battery life won't suffer from using the Nvidia card as your main card.
Your laptop is most likely using the correct drivers for your intel card currently or using a generic one.