samba & NT administration issues

[Lubomir]

I have samba 2.0.7 on RH7.0 Linux box acting as PDC for 40 NT4 SP6a 
workstations.I have some difficulties here and any help would be 
appreciated.

1. More than one users are allowed to logon at the same time. I want 
just one.No more. May be right samba option is missing?

2. I want to delete roaming profiles after user logoff and save them on 
samba server. I tried this:

[profiles]
...
root postexec = /bin/rm -rf /samba/profiles/%U

but it didn't worked. Is there something I am missing?

3. There is "c:\temp" directory on WSs (name tells purpose) and 
"everyone" is given "RWXD RWXD" rights. The problem - a ordinary user is 
able to create directory there and he can remove all rights (for admins 
and system too) he wants on it. Then even with administrative user 
rights I am unable to delete dir or change the rights!
  I added "creator-owner" with RWXD RWXD rights on c:\temp but it didn't 
worked. It turned out the true owner of new directory is not 
"creator-owner" but "account unknown" who obviously has full rights. 
This user was authenticated by samba PDC but can't be determined by NT 
WS (it refuses to add this "account unknown" in directory permission 
list of c:\temp and it can't be given any rights).
I want to disable changing rights and ownership for files and 
directories in c:\temp for ordinary users or just be able to easy delete 
them. Maybe there is some workaround (some policy key I don't know!) for 
this.

4. The same linux box is squid proxy which is cascaded on another proxy 
in separated network. I want all users to be able to browse sites in the 
other network but only autenticated users to have access to the 
internet. Can you recommend me solution?


Thanks in advance!

---
Lubomir Velkov
University Of Rousse