Try to replace sd:\bootmii\ppcboot.elf with one of these. The are supposed to boot system channels via bootmii. See if you can get one to load and then sync the wiimote. Let me know how it goes.
Also when you formated the nand.bin, you did have it install a system menu, setting.txt, checked it with nandbincheck. Just checking because you need to install system menu after the format.
If your nand.bin is good, passes nandbincheck and your wii still does not work your bt module may have gone bad. If the bt module was bt system channels probably will load to black screen. Also when you nandbincheck, have a look and ensure the system channels title id are installed for what you are loading form the above pack.