Nordica Blower Ski Boot - Men's - 2008 BCS

28 sounds large for a size 10 foot... regardless, the first thing I would do is find a professional bootfitter as opposed to someone working at a ski shop (most shops should be able to recommend an outside 'fitter). It's possible that you could be fitted with corrective insoles that would compensate for at least some of the pronation by supporting what I assume is a flat foot. I would avoid messing with the inner padding as much as possible because it will affect the overall fit. Changing the position of your foot, however, shouldn't alter the fit around your ankle but will center it more over your foot.

Sole Length: 285mm [24.0/24.5], 295mm [25.0/25.5]

It depends on your preference. Usually a stiffer boot is better for a more advanced skier, allowing more power transfer and edge control. I personally ski on a softer boot, flexing around 110. If you are used to a stiff boot or want something with more control, then this is a good choice.

Yeah they changed the flex from last year. Last year 07/08 model had a flex of 115. Also the smaller boot sizes from last year had a front spoiler that was removable. This year I believe there is no front spoiler. So this years boot is slightly stiffer with less ability to soften it up.

27.5 in a Mens size. or if womens 26.4 look at the sizing chart.I would definitely go smaller than a 27.5... Most people go down at least 1 size, and sometimes 2. I'm a size 11 shoe, and wear a 27 boot. Also, keep in mind that it's always easier to modify (grind out) a boot that's too small and maintain a precise fit.