From your description, there is nothing you can do for the wii. If the gc controller did not work with savemiifrii a modchip will not help. How did you downgrade to 3.3? Was it 3.3K or 3.3u, did you install ios40 or ios30 first?
Either way, if you can send it back to Nintendo, that is the best option. Also, don't feel bad about bootmii, korean wii's don't support the boot2 install so it would not help, neither would preloader.
If you do get a new one, post here and I can help you region change it.
If you boot the wii and see the health and safty screen, then it goes to black, this can be fixed with a modchip- preconfigured to autoboot. It also means that you are doing savemiifrii wrong.