Yes any student can have his own sparse disk anywhere in the network.
But working with sparse disks need some understanding.
First a sparse disk image is a kind of "virtual volume" located on a another volume as a file. If you double click that file it will show up in the Finder as a new volume which can be used like any other volume directly attached to the local machine. Like any other volume it will have it's limitation in size.
For example you got a 2 TB internal drive and you want to create some sparse disk images on it. What you can do is to create 3 500GB sparse disk images leaving 500G free for the OS, apps etc. Once the 3 sparse disk file are created they only cover a small amount of disk space - cause they are empty when you created them. Now working with them will let them grow (regarding used space). If you add more files to the internal (or external) drive will leave less space for the sparse disk images to grow to their limit maybe. Therefore the 500GB in some circumstances can't grow up to 500GB cause there is not enough space on the "master volume".
The other thing is that once the sparse volume grow up in size it will keep this size. You can delete files on the sparse volume but the current space used for this will keep the same coverage. You can shrink them using some terminal commands (or my app).
The other thing is that the 500GB (in my example) is not enough to hold a certain project and FCPX will give you an error. This can be fixed - as long there's enough available space on the "master volume" - by some terminal commands as well (or with my app with a click).
So go and try some some of the scenarios before you start and make sure the students understand what they do and can do.
Andreas
Spherico
http://www.spherico.com/filmtools