After quite some work and testing i came up with the following squid.conf:

visible_hostname example.com 
cache_effective_user proxy proxy

## Elite Proxy settings 
forwarded_for off
request_header_access X-forwarded-for deny all
reply_header_access x-forwarded-for deny all
via off

## caching options
cache_mem 100 MB
maximum_object_size_in_memory 512 KB
cache_dir ufs /var/spool/squid3/ 800 16 512

## Access Control Lists
acl Safe_ports port 80 # http
acl Safe_ports port 21 # ftp
acl Safe_ports port 443 563 # https, snews
acl Safe_ports port 70 # gopher
acl Safe_ports port 210 # wais
acl Safe_ports port 1025-65535 # unregistered ports
acl Safe_ports port 280 # http-mgmt
acl Safe_ports port 488 # gss-http
acl Safe_ports port 591 # filemaker
acl Safe_ports port 777 # multiling http
acl Safe_ports port 631 # cups
acl Safe_ports port 873 # rsync
acl Safe_ports port 901 # SWAT

http_access deny !Safe_ports
http_port 3128
acl localnet src 192.168.178.0/24
http_access allow localnet

This provides a minimalistic and well working configuration for my debian Server