Well, this may sound weird lol. But this problem has happened to me like last week. So I was just testing stuff out and put some alchohol on the GC controller. It may actually work since maybe the controls inside are jammed and it may loosen it. Just please try it at your own risk :). Don't wanna be blamed for anything lol.

Well, whenever you enter your Super Smash Bros. Brawl game disc. Just press the "Home" button on your Wii-mote and go to your Wii-mote settings and press the button "Reconnect" or something like that =P. Just keep repeating this process till you get it to work or you could open the battery compartment and press the red "Sync" button on the Wii-mote and the red "Sync" button on the Wii located in the SD card slot at the same time. Just keep repeating this proccess.

I don't really know the answer to this. Sorry, but this may be due to the Wii's reading and sending data to the Wii-mote due to Super Smash Bros. Brawl's large file capacity. So there is likely an issue with your Wii console. Only way to fix this is by sending your Wii to Nintendo which I do think you should do since your getting all these damn problems with the Super Smash Bros. Brawl game. You could just call Nintendo by looking at the back of any Nintendo game case =P or it'll be easier to just click here for the shipping form for your Wii. Nintendo says that your Wii will most likely take a week to arrive back to you. I suggest you call them as well so you don't get all confused.