Yes, OS X is secure. As secure as an OS can be - out of the box.

Still, there are things missing. Some for legal reasons (stupid regulations on strong encryption in many non-democratic countries for obvious reasons), some because of - umh, dunno - because TheSteve did not think it necessary.

Or because some software folks like to spy on you and have their apps phone home interesting details about you and your Mac.

Not sure.

Anyways: here you get the tools to strenghten the walls, control inbound and outbound traffic, encrypt your files and emails and to all the good stuff secret "agencies" and other spooks don't like.