In my youth I'd endlessly try to optimize things. You should see my fvwm setup. "Chef's kiss" perfection.

Regarding 2 keyboards -- mostly it just works. Try it. If you're like me you probably have a stack of random garbage keyboards within 30 feet of wherever you've got your work desk. Plug 'em in and type away. For me, anyhow, it works just fine - my left hand doesn't actually need to be within a foot of my right hand.