There is no single magic EQ curve that makes everything right.
Agreed, there is often something to be said for cutting out some instrumental mids to make a voice stand out in the mix without being too loud, but really, you have to use your ears to decide what's right every time. The "smiley curve" is a well known phenomenon to sound engineers, but it's not universally regarded as the right thing to do.

There's also a lot to be said for cutting the extreme bass, where the only sounds recorded turn out to be noise that has nothing to do with the music, and for cutting a lot of bass on individual instruments that don't produce any. No point in having anything below about 200Hz for a whistle or a fiddle, for example.

Going back to the live recorded session - yes, the best mics in the world, placed randomly in a mediocre room, will not produce a studio quality recording if you are expecting the clarity and balance available with separate mics on each instrument. Conversely a portable recorder can give excellent results in a live performance setup if you can find a position for good live sound, and place the recorder in that position.

Interesting about men and women hearing differently - that's a new one on me. Going to go Googling for more about that...

Anahata (also both a musician and sound engineer, these days)