it's funny how things like this evolve ... for me, i've gotten to the point where as long as i can a) hear my guitar direct from my amp and am reasonably pleased with my sound, b) hear my vocals and all the other vocals in the monitors (for harmonies), and c) hear the drummer (never a problem) then i am good to go and let the sound guys take care of it out front .. i've given up on getting a balanced stage mix at a tolerable volume ... with 2 electric guitars, acoustic guitar, and keyboards all trying to fit into the same freq range, it just isnt gonna happen at our low $$ level rental PA amateur level
just play and have fun unless there is big $$$ involved to pay for higher quality sound
cheers
t4d