Well, unless your armor is made of aluminum foil, or the fire is ridiculously hot your metal bits will be fine. That said, imagine the havoc it would wreak on your heat management.
Not generally true.
This is what happens to large structural steel beams in a typical fire:
Keep in mind aluminum, a great spacecraft material, has a much lower melting point. Titanium, also good, wouldn't suffer from this at all. Steel may melt into liquid
at a few thousand degrees F, but it becomes worthless as a structural material at only a few hundred degrees F. Not to break anyone's conspiracy bubbles, but that is how a steel building like the WTC could be weakened to the point of collapse from a fire that was "only" several hundred degrees.
It's possible that there wouldn't be any force to cause such a deformity (no gravity). It's also possible that your pressurized hull would rupture like a soda can at the barest glancing blow or acceleration, and it'd stay melty-hot for quite some time without a way to get rid of the heat. Also, many other substances you'd find in a spaceship (plastics, exotic metals, hydrogen fuel) ignite at temperatures far lower than the ones I'd expect in a regular fire.
Also, I saw a thing on NOVA about how JPL is testing anti-meteorite armor that is mostly foam and (what appears to be) aluminum foil (basically a Whipple shield with solid material between Whipple plates). So it is actually possible most of your ship is not
steel but is, instead, aluminum foil.