Hi, to answer your questions, I it really depends on what type, or category of A/C you're talking about. What I think you'll find those questions are really type specific, with a few generalizations.
I currently fly 3 turboprops (I know, way too much review required), and they are all different.
In the Saab pulling the T-handle will silence the warning, close the fuel shutoff valve, close the bleed valve, open the generator relay, arm the extinguisher squib, and reset the master warning system.
Where in the King Air, the "Firewall Fuel Valve" is just that, it only cuts off the fuel at the firewall (before the low pressure pump).
Normally the Pratt turboprop engines are shut down by cutting off the fuel after the Fuel Control Unit FCU (GE calls theirs an HMU), this is done by the condition lever, while the T-Handle blocks the fuel before the first pump.
Cheers,
ftp
edit: poor coherency at 1am