Yes, a gate in the POST section will clamp down preamp noise, which is what you're hearing.
Unfortunately, no. But, you probably wouldn't need to use all 8 blocks on a high gain patch, right?
I did ask for the ability to put the global noise gate at different locations in the chain in a thread. Don't know if FAS saw that request because I don't think I started a separate tread to specifically request it.
Did you try the pad level? This fixed another guys hiss problem
I use an ISP Decimator G String first in the SEND loop. That's the secret. Don't bother with blocks, etc. Just get the ISP Decimator II G-String, or perhaps the new TC electronics gate (price is nice, features much like the G-String) and never worry about this again. Not sure how you ever survived with that noisy of an amp without it.
But. Isn't the purpose of getting the FX8 to get rid of pedals not add pedals? These guys are awesome they will figure out a global gate for us gainiacs with snakes in our amps in time..