Over-voltage protection

[amgen]

well, the 7805 takes up to I think 32 volts at the input so you could use any adapter that is under that voltage with only exception that the input has a minimum of about 1 volt over the regulated 5 volts. Those TVS and MOV's are generally used for possible heavy surges of power and lightening type events, and even then, the electronics can be damaged due to "instantaneous power/voltages" that strike. The NTC, when used in power circuits, are also called "inrush current limiters" are generally used for limiting "initial" current inrush if there are large capacitors to charge or motor or transformer windings that may take large startup current. The resistance for NTC's goes down as the device heats up reaching the 'steady-state' current. Lastly, there are 3 terminal linear voltage regulators with a higher input voltage ratings, if that is a worry.
ps: that is a pretty circuit you drew !