Re: Every live sound engineer should spend a little time in a recording studio.
1-6!!
All good reasons to have as solid as possible reference of your target mix in your mind. My new saying for quick gigs especially is now..."Make space...and then make space."
Space 1 - assuming the system is reasonable balanced, actively begin frequency layering of the mix and dynamic processing.
Space 2 - create spaces (time domain) for various elements of the mix. This part may need to seem exaggerated at times and 'larger than Life' stuff can be VERY effective but needs the hand of human automation riding things constantly.
The is more work than I see anyone doing at shows I endure. The good part is it gives us creative and dynamic tools which we can you to be truly artistic with our live mixes. When this coincides with right performance, people react!
All these things support the basic premise that...knowing more is the only position from which you can properly decide to do less!
That is different than someone knowing AND therefore doing less.
If you know how the drum mixes or vocal mixes from different styles of music are created in the studio, you are gonna be better than someone who doesn't. Regarding Space 2 from above...I don't know one single Sound person who describes creating space by using real spaces in the description! I once mixed a solo trumpet playing taps at a memorial benefit and the player asked me afterward why the sound was so effective? I told him I visualized the Reflecting Pool at the Lincoln Memorial and the surrounding space.