No Rob, I'm running Windows 8 PRO.
Actually, I have at least 20 machines running the Adobe CC on Windows 8.
On the Flash of many of these machines, happen this issue.
When determined tool is activated or simply used, a "terrible" lag (something around 5 seconds) occurs.
This doesn't happen in every machine, but occurs in machines that have or not have update installed.
I don't think there's been an update to Flash since Windows 8 came out. Did you check the compatibility with your existing software before installing a new OS on 20 machines?
start terminating running processes to see if you can find the culprit.
In fact we reciveid a lot of updates through Application Manager. So I do think the problem is the lack of one update (maybe, I don't know realy).
But, just like you sad, Windows 8 is not listed as an OS supported by the Flash CS6. Yet, I don't think the problem is related to this, because I faced a similar problem (if not equal) in a machine running Windows 7 (with recommended requirements).
I'll try to start the Windows only with the basic to see if the problem still persist.
I have this same problem, any application on fonts (filters, size, embed) has a 5 seconds delay.