Hey, Hooie Costa, if you ever find boots that fit your feet, your a lucky man. Boot manufactures suck. The key is that they should be like a second skin. There should be no play anywhere but they shouldn't feel like your foot is in a vice either.
Any where there is ANY slippage will probably develop into a blister. Heels are a problem often. The boot should 'cup' the heel. It seems that many of the modern boots don't cup as well as the older classics. The heel of the boot seems to be too vertical. You need curvature to match the heel of your foot.
Width is another problem. Mens dress shoes come in multiple widths. Why don't soccer shoes come in multiple widths where fit is even more important??? Money. Cheap bastard shoe companies.