hate to nag, but did you buy these boots online? Going to an actual board shop will usually provide you with experienced info on how a snowboard boot should fit (toes grazing the liner, open toe box, etc). A good boot fitter will get you the best possible boot for your particular feet...or suggest the best boot, if not in stock.
of course, having the best/proper fit in the first place is priority #1, but changing out the factory insoles would be next. From my exp, even the fanciest stock insoles aren't as good as Superfeet and other third party sports insoles...just make sure you get the right arch height (superfeet green are high arch, blue are medium, etc)