sudo pmset -a destroyfvkeyonstandby 1 hibernatemode 25
Will destroy the FV2 keys stored in memory when the computer sleeps. This ensures that they cannot be retrieved by somebody who has access to the machine and the know-how to get the keys from the memory which is no easy task, but nevertheless if they have the time and access to your machine, they can accomplish it.
Since I found this out myself, I have began to use TunnelBlick with the strong OpenVPN settings here: https://www.privateinternetaccess.com/openvpn/openvpn-strong.zip
I can report my machine sleeps properly and destroys the FV2 keys in memory successfully as soon as the lid is closed or I press the Power button for a second. Also the strong OpenVPN settings don't slow my connection down at all. I can also confirm that my connection displays the correct IP when connected unlike the PIA app. Until the app is fixed, I will no longer be using it.
The settings for installing TunnelBlick are here: https://www.privateinternetaccess.com/pages/client-support/osx-openvpn-tunnelblick
For more info on the code I've provided above, visit this link: https://apple.stackexchange.com/questions/169272/removing-filevault2-key-from-memory-on-lid-close
For disabling IPv6 directly in settings of OS X, see here: http://help.unc.edu/help/how-do-i-disable-ipv6-on-mac-os-x/
Using NoScript, Privacy Badger and a trustworthy Adblock service, (which you really should be doing anyway) you will have features resembling "PIA MACE" option in the PIA app.
The only option which I haven't been able to replicate is the VPN kill switch. I'll update this post as soon as I find a great method of doing so.
Installed a couple of days ago. It says Preventing Sleep while it's disconnected. Is this normal?I'm on OS X.