None not needed at all

Let me see

Even if i open that sites , It would not infect safari and let alone opening the .exe. So I am safe. No browser hijacking

ActiveShit + M$ VB = nope...It does not hijack


Firewall , yes its a must have . It does not matter if its OSX/Windows/*nix. All *nix system comes with a solid foundation . But again if you're hosting somethings. Its better to have Firewall. OSX comes with bulit-in firewall which is very good. If you have a router, you have a hardware firewall and you can safely switch the OSX firewall (unless you're paranoid)