If the fuel switch, not the transfer selector was off, someone in the plane turned it off. Considering how the plane augered in, it could have been knocked off before or after impact. It is just a switch. According to the recovered engine tach measuring engine RPM, the engine was delivering power all the way down. Like a broken watch, it is busted @ the top of greenline about 2700 rpm.
As for SAR, the only things they usually remove is the people. If recovering the aircraft salvage and safety guys want everything in the position it was at impact so when they re-assemble missing pieces stand out.
After a crash, unless the Iranians are on film putting a couple of Tor-M1 SAMs into you, if you die, the accident will be your fault.