Warm to the touch is normal. Hot is when it's almost too painful to touch.
Any chance the noise you hear is static from speakers?
Considering the monitor's housing has a wider gap in the lower left corner at the edge as in popped open a bit, I dunno, maybe when it was assembled it was all tightly held together, and a little heat was all it took. Or maybe it was always like that and I never noticed. As long as it keeps working its all good I guess.