Welcome to the Apple Support Communities
You don't need any antiviruses for OS X because OS X has got its own security systems. See > http://www.reedcorner.net/mmg
However, if you want to install an antivirus, we only recommend ClamXav and Sophos. Other antiviruses just can make your computer slower and, in some cases, damage OS X.
Note that this only applies to OS X. If you install Windows on your MacBook Pro, you have to install an antivirus in Windows to keep Windows safe from viruses. In this case, I recommend Microsoft Security Essentials
The firewall doesn't interfer with FaceTime conversations. If you want, you can turn it on, but it's not needed, too. It won't harm your Mac, but probably you won't notice any change, apart from getting windows to allow or deny connections.
A better application to monitorize what's using the Internet in your Mac is Little Snitch
Does the firewall in the security settings need to be turned on in a new Mac pro notebook.
There has been some not quite right advice being passed out here.
As long as you are behind a router on a trusted network you do not need the firewall to be turned on. In fact leaving it on will slightly slow down your network access. See Do I need a firewall? and paragraph 9 of Linc's posting.
If you are on a public network then it would be smart to have it turned on, especially in a place like Starbucks or a public library where hackers might be nearby attempting to intercept privacy information from over the Wi-Fi.
But both your router and your MBP have incoming firewalls to keep connections from getting in. Little Snitch is exactly the opposite type of firewall, to keep processes on your computer from opening a connection out of your MBP. You definitely need the former and may benefit from the latter.
Link, your issues with Avast are getting out of hand. Go do some reading and even install the new engine on a test system before you use your old biased findings to spread crap to new users. I'm tired of everyone stating that Macs are impervious to viruses and malware. They're not and you're not!
Go read the reviews on CNET for Avast and then your precious ClamAV. Clam has a whole 78 reviews, Avast for Mac has 571 and 23801 for PC and the average is 4.5 stars.
Bottom line, whatever didn't work for you or other in the past is working now. The new engine is much better and it'll continue to get better. The public release of it for Mac just happened a few months ago, so it's not been out as long as the PC version has. In the PC world, Avast and AVG are the two trusted free solutions on the market, with Avast being the one that's not canibalized with ads and limitations as AVG is. People should be free to make their own decision, but spreading flat out lies is BS in my book. Get off your soapbox with your copy/paste posts all over the place. If your posts are such gospel, maybe you should get the mods to sticky them or something... seems to me all you do is just post the same book time and time again for every single daily new member who asks about AV... and none of it is truly 100% right.
You can't safeguard "stupid" by telling people to just be careful and not open stupid things they see or get. Heck, how many people fall for the MacKeeper ads? The idea of AV and AntiSpyware programs runninig realtime scans in the background is to keep people safe from their own misuse.