By disabling them, you're damaging the security perimeter of your network. Allow users on the firewall system. Firewalls should be as simple as possible. Users add complexity. Every user account is a potential avenue of attack.
Every user is a potential attacker.
Every keystroke of every user has the potential for opening a breach in the firewall through user error. Allow a lot of people to administer the firewall. Too many cooks can spoil the broth. The same goes for firewalls. Every dial-in modem behind the firewall potentially circumvents the security perimeter.