[squid-users] simple questions?

Hi,
My squid finally is run,and also I could run cachemgr.cgi at my
squid.config is the below:
But
1.even I set cachemgr_passwd 12345 but without password all my user can
access to my cache?
2.all my client can go trough my cache to internet but I cann't see them
in my cache manager at client list?
3.how & where can I find cache server for cache_peer such as cache_peer
proxy.uk.planetsky.com parent 3128 3130 no-query default ?
4.i see this line in one of config file , what does it do?
refresh_pattern -i \.(html|htm|shtml|phtml|pdf|asp) 0 45%
43200
refresh_pattern -i \.(mov|wav|mp3|mp2|avi|midi|ram|au|mpg|mpe|mpeg|dat)
129600
            900% 129600
5.how can I install mrtg for squid?
Where my config is incorrect ?
 
Please see att.file for :my squid.conf
 
Best regards,
Please send me, as soon.
I looking forward to you,
M.Kabiri.