We did not have to open any new ports on the firewall to support the plug-in.
I understand that the document doesn't specifically mention the Office bit-ness. All I can say is I had everything setup the way the document describes and it didn't work. Once I matched my Lync client bit-ness to the O.S. (Win 7 Sp1 64 bit) it started working.
I'm only speaking from my experiences and trying to help. That document is a v1.0 so there is potentially some tweaking needed.