1. Is there any way to transfer Fo3 character to nv?
2. Is there any codes to use on the xbox 360 to modify character or give items, seems strange can do on computer but not an option on 360? There must be a programers test console for xbox 360.

1) No, You can recreate your character with effort, but it's a brand new story so you can't import your old Fallout 3 character.

2) No. Due to the nature of security on consoles, Most Devs do tend to disable the console for console games, such as in this case.

Only way to do this is to mod your save file. Possible, but not for the lazy or faint of heart.