question nr 1: it depends on what you mean by "regardless of location" and if by location you mean US v the rest of the world, the buyers from the US do sometimes enjoy more advantages than buyers from Europe (e.g. the freebies, which are always priced $2.30 for me, and i'm from Europe). i'm not sure about other books but i do recall people upset that buyers in the US pay less for ebooks.
british buyers say books are occasionally cheaper on amazon.co.uk than they are on .com, etc, etc, etc.
question 2: a definite no this time! but it's not amazon's fault. rather the pesky geographical restrictions are to be blamed for this major hassle (read turf wars between publishing houses).
however, there are books which only we can buy and the americans can't (can't think of a title right now though
. it used to be the case with the millennium series by stieg larsson)