only thing that drives me crazy is when I accidentally click outside of the screen it open the overlay. would also really like to be able to turn down graphic settings, to cut down on some lag.
easist, but longest way to beat #4 is use rain of arrows and nothing else... get the timming down to where the arrows hits the boss b4 he his your boss, don't waste time any of your guys, just use rain of arrows. If you want to speed up the kill add casters that stand behind your boss.