AC - with regards to your last point. There is a residency calculation that you must do for both your US and "X" country (in your case Belize). Every country that I have heard about has this. In some cases (as in mine) you may be subject to "double residency". In my case this means that I still pay taxes within the country that I reside in the most (not the US), but on a reduced scale. If I choose to claim the "ex pat exemption", anything under the 91k is not taxable by the US and anything over is. But if this is claimed, certain benefit's are lost (funding IRA's, local deductions etc).

Tax laws are always decades behind business innovations, which is why this comes up all the time regarding internet businesses. Between accountants and lawyers in both countries (not Belize), I still have not received a real hard answer. But I do know the check-list and formula the IRS uses to determine where/if you "do" business in the US and you should really check into that. It's too long to post.