Thinking out theory for secure ssh

[RobinVossen]

Well, I run a ApplicationServer. And they settings has to be saved on the localbox.
So I want to mount the /home folder on connect with NFS.
I want to connect using SSH -x and I want to mount NFS only ONCE.
Since if you mount over eachother you'll get a mess.
Thus, everytime a user presses a icon the client makes a passwordless connection over ssh 2(Blowfish) using the -X <progname> parameter.
Then I should put something in like:

if (firstconnection)
{
    MountNFS (Using Kerberos)
}
else
{
  DoNOTMountNFS
}

But when the last connection stops he has to Dismount the homefolder.
So I got with this Pseudo Code:
[code]

if (firstconnection)
{
    MountNFS (Using Kerberos)
    while (connected)
    {
         wait();
     }
     umount NFS
}

But that will kill the CPU since of the Never-Ending loop.
And then again. Were should I put that script in then?

Can somebody help me with the Theory on how I can do this the best way?
Everytime a user clicks a button a NEW and extra tunnel is made.
and the NFS share is only allowed to be mounted once.
And on disconnect the mount should be unmounted

Oh, and a tricky part comes now.
this isnt needed. But its a pre if it can be done..
If the user doesnt exist yet. Then It should be reported and the user should be made by the system..

Well,
Cheers,
Robin