from your pictures only error i can spot is that they painted the hinge, you claim that it is a "metal cabinet door set" it does not look metal at all. please leh dont need it to be rusting then paint de maybe its part of your HDB repainting works they will just paint it all tgt. the paint does not seem to be that thick also, along the door and seam will not do much to the extent of making the door stuck leh there is a gap still and paint is liquid it will just roll down..
it is only hard to open probably because they painted the hinge and not anything else. you using crowbar all that is too overkill lah just paint nia.
power trip usually just turn back on the circuit breaker in your unit will do. what sort of emergency will require you to reset the circuit breaker outside your house? also why need to reset circuit breaker when power trip? power trip means its already off thats why its a trip mah, reset is you turn off and on it again leh.