Just to clarify a few things -
In the configuration of the pumps that was evident after the accident 4 CAD captions would/should have been illuminated?
FWD F PUMP
AFT F PUMP
PRIME PUMP (BOTH)
As to the Emergency Shed Bus switch being inaccessible or hard to find?
If you actually READ the RFM you would have activated it to test for a fuse failure in the EMB prior to each flight? So it should be second nature.
A note - it is not in the pre-start checks but in the pre-flight check.