drivers - Laptop Nvidia Bumblebee clarification

So this is partly clarification (to help future users) and partly questions to make sure I understand what's going on.

Recently attempted to make the switch from MacOSX to Ubuntu as I can't afford Mac hardware for my purposes (using Blender 3d open source graphics program). I'm selling my Macbook Pro & have bought an Optimus IV custom build laptop with integrated Intel graphics & an Nvidia GTX660M, i7 etc. After fruitless DAYS trying to successfully install Nvidia drivers on a clean install of 12.04 using all methods I could find I decided I'm not savvy enough for Ubuntu to be my primary OS for my work and couldnt risk it (using 'Blender').

New plan, 2 hard drives;

1st SSD for Windows 7 upon which I'll be running my work (Blender) exclusively & thus reliably

2nd HDD for Ubuntu, it looks like a great OS that I'm keen to learn & get to grips with for the future and I'll be using it for 'everything else' docs, file management and so forth. Would still like to get the graphics to work on it though.

Today I clean installed 13.04 (I thought as it's newer, Nvidia might play nicer). No proprietary drivers have ever been recognised by Ubuntu on either 12.04 or 13.04. I take it that Ubuntu isn't recognising my Nvidia card natively..

After reading this very informative article on Nvidia drivers, I first tried installing Bumblebee and things for the first time seem to be working, - I can 'switch my Nvidia card on':

Now when I run glxspheres I get a framerate of ~60fps (intel Ivybridge Mobile)
When I optirun glxspheres I get a framerate of ~120fps - OpenGL renderer (GTX660M/PCIe/SSE2)
The instructions seem to be that, whenever I wish to enable my Nvidia GLU for increased performance, enter terminal & type eg optirun chrome, or optirun blender etc. depending on which application I'd like to make use of it..

Great.

My questions now:

1. Do I need to 'switch it off' afterwards, or just exit the application?




2. I don't play computer games. Since I'm going to be using my Windows OS & SSD for running Blender and video editing (as I can rely on it) which applications would you recommend I use the optirun command for in Ubuntu? Watching youtube videos? Watching VLC videos? Streaming from Ubuntu via HDMI to my TV? Or is the Intel integrated GLU capable of comfortably dealing with those? Even if the Intel is capable will the Nvidia GPU give a better performance?




3. When I installed Bumblebee did this automatically install Nvidia drivers or is running 'optirun' switching between Intel drivers and Nouveau drivers?




4. If switching to Nouveau, I'd like it to download and enable Nvidia drivers for better performance. I've tried to see which Nvidia driver is recommended for my card as advised in the article above using:

ubuntu-drivers devices

ubuntu-drivers devices | grep recommended
however nothing comes up..

From reading, looks like I need to run:

sudo add-apt-repository ppa:ubuntu-x-swat/x-updates  
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install nvidia-319  (I've read this is a good package for the 600 series cards). 

I think something that's confusing about Ubuntu are that there seem to be 5 ways to do the same thing, I've seen commands that recommend 'install nvidia-current' etc & that this will automatically pick the best drivers for you, seems to be a lot of conflicting information.

Seems like I can install primus according to this article
sudo add-apt-repository ppa:bumblebee/stable
sudo apt-get update
sudo apt-get install primus
sudo apt-get install primus-libs-ia32:i386

However what's confusing here is that my Terminal, when installing Bumblebee, also instructed me to change the bumblebee.conf

5. Why?

A lot of real basics I'm trying to understand here, your patience is much appreciated.
Laptop Nvidia drivers Bumblebee Optimus Primus