Cloudflare said on their wall on Facebook that they were going to leave the site up, as a means of checking how browsers deal with revoked certs: https://www.facebook.com/Cloud... So Firefox is probably doing the right thing here. Last time I looked, Chrome didn't display any warning. Which is nice.
When Mac and Windows users complain that Linux doesn't work, I really don't know what they mean; my experience of late has been that I have fewer annoyances and more things just work, with little-to-no need for configuration when using Linux. (Computers in my household running a mixture of Win 7, 8 and Debian at the moment.)
FreeBSD? On a desktop? It's do-able, but if the OP thinks that Linux falls short in the 'it just works' department, he/she's not going to enjoy the FreeBSD desktop experience.