Never thought about that, thanks for the heads up.
Probably, no electronics should be inside the enclosure. For 3D print the major reason for an enclosure is to allow high temps build inside for ABS and other filaments. Electronics probably limits the temperature you can use below 40-50 degrees celsius.
Yes you are right. I was going to put the A350 PSU inside due to the noise, but now that really is not a good idea.