Hi guys,
well first of all, regarding the statement
"no elec power => no pumps => no hydraulics" is not quite correct, as you still have engine driven pumps (they don't require electrical power, and will be powered as long as the engine are running or windmilling)
So, yes, a B767 can be flown without electrics. Even further, a B737 can be flown without hydraulics, as the flight controls are directly connected to the control surfaces.
The functioning of the RAT depends on aircraft. While on the Bus it does power elec/hyd, it will only power one hydraulic system on the B767. On the MD-11 I believe you have the option of choosing hyd or elec from the RAT.
Some B767 fans may now say, hey, if the C Hyd Sys is powered by the RAT then the HMG (hydraulic motor driven gen) can power its busses. Unfortunately, the RAT only supplies the primary flight control surfaces thus no additional electrics from the RAT.
Regarding total loss on the glass-bus (elec & hyd), yes, rudder and manual pitch trim will still work. Its even taught in the sim (triple hyd failure is not taught on the 767).
Hope that helped,
Regards,
Mark