Sandbox Questions

[atad6]

I've read the SD manual and want to create a sandbox setup on my machines using separate partitions on a single disk. I just am a bit confused when it comes to how applications are shared. All of my applications are under the /Applications folder which I think is the default for osx and allows the applications to be accessed by all users. According to the guide using "shared users and applications" keeps the applications and user files on the original volume and allows them to be accessed from the sandbox using aliases to save space.

I'm confused because in the "Maintaining A Sandbox" section it says all the files saved in /Applications are independent to either the sandbox or original volume. I want to have a setup so that the applications are running off the original volume to save space, not on both partitions.

Also, I was wondering if using sandboxes are a good idea for a machine that is used by multiple users. Won't having two similar looking partitions mounted to the desktop be confusing to other users? Users with standard permissions don't have the ability to modify system files on the original volume do they?

Hopefully this isn't confusing, I'm just trying to figure out the details of a setup like this before I start.

Thanks!