SECURITY Questions !!!

I am running CSF firewall on the HW node and it has a checkup script which does some checks and suggest some solutions.
Those checks are primarily designed for a common LAMP server and not for PROXMOX, however this is a question to the staff:

Will those suggestions break something if I implement them?

Suggestions:

1. WARNING /var/tmp should either be symlinked to /tmp or mounted as a filesystem
2. WARNING /tmp should be mounted as a separate filesystem with the noexec,nosuid options set
3. WARNING /dev/shm is not mounted with the noexec,nosuid options (currently: nosuid). You should modify the mountpoint in /etc/fstab for /dev/shm with those options and remount
4. WARNING You have a local DNS server running but do not appear to have any recursion restrictions set. This is a security and performance risk and you should look at restricting recursive lookups to the local IP addresses only

No4 is really strange as I don't have DNS server running! Unless something is there which it shoudn't.

Comments?