Sorry for the repeated questions - this thread is pretty long.
From what I can tell, you have the following setup - please verify:
VM OS: Windows 7 SP1 (64-bit), MS Office 64 bit (with Lync 2013 client)
Client OS: WIndows 7 SP1, with Lync VDI Plugin (32 bit)
Horizon View client - 64-bit (please verify the version of the View client)
Things to check:
1) on your client machine, make sure you have correct registry configuration
2) make sure your client machine can reach the FQDN of the Lync 2013 server
3) make sure that you DO NOT use USB redirection
4) make sure that you are not running a Lync 2013 client on the client machine (this will interfere with the Lync VDI pairing process)
A couple of other notes:
1) You do not have to open up any additional ports. The Lync VDI plugin pairing process works over a virtual channel, so no new ports need to be opened up.
2) You probably checked this already, but did you verify that you installed the certificate on the client machine?
A couple of known issues also:
It's a known issue on Microsoft's side (http://office.microsoft.com/en-us/lync-help/lync-2013-known-issues-HA102919641.aspx):
Lync Windows Store app can’t connect if the time setting on the device is not in close synchronization with the time setting on the Lync server
Sign-in will fail if the time and date on your device is not set accurately. This is particularly important for devices that are not joined to a domain, such as Microsoft Surface or other devices running Windows RT.
Workaround Set the time on your device to within 5 minutes of the time and date on the server. It is not necessary to match the time zone.