1) Can I buy a 760/860 from Japan and use it in America(Hawaii)? Do I have to load another rom like OZ. I've never tried that yet on my 5500.
You can convert most of the stock software to english without reflashing.
2) Can I use my 5500 apps on the 760/860? I've bought some from the Kompany and I assume I would have to get other ones since they seem to have a different pick. Are all apps like this?
This depends on the app. Much of the Kompany's stuff has C7x0 specific versions, but most apps should work fine.
3) I'm going to be staying at Ikebukuro,but I 'll go any place in Tokyo to get one. In another post some people were saying that 7xx were going for $350 and the 860 is going for $700. From what I read, the major difference between the 760 and the 860 is the ram, but what about the 750. Does anybody know where the $350 760's are sold?
The only major difference between a 760 and an 860 is the software ( the 860 has some different software) and the color scheme. Other than that they are identical. The difference with the 750 is the ammount of flash ( storage space) and the size of the battery that is in the box
4) Do all versions (750/760/860) have a usb host?
None of these devices have usb host support