I could help you out a little. I have the same sony s series, though an older one (VPCSC1 series). but I use the PTV2000 from netgear. so try this:
1. forget about the intel chipset or realtek or audio drivers - those are of no consequence for widi operating correctly.
2. the only drivers you need from sony's site is the graphics driver, since that is customized to support intel +amd switchable graphics. So make sure you install the latest graphics driver from sony's support website.
note: sony may not support the latest intel graphics (9.x) which is perfectly fine. DO not install the intel graphics driver from intel directly - it is not customized to your laptop. in case you already have done this, use system restore to revert your system back to a known good state in time.
3. all you need then to do is pick up the latest intel wifi, intel widi drivers directly from intel. (though your wifi driver is ok, even though its not the latest). try and remove intel widi completely and the reinstall the intel widi software and check.
also check this thread I had made about how to reactivate the virtual adapter for my wifi to work correctly: