Black screen when starting a game = missing or out dated IOS file => Check what IOS and (minimum) version the game need.
Is bootMii installed as boot2 or IOS?
Can you make a backup of your NAND? Do it.
error -1029 = bad WAD file or old WAD Manager (what IOS do you load in WAD Manager?)
Pimp My Wii = Brick My Wii....