Delete all nincfg files? Where else can nincfg files be found besides the SD card? I took the picture directly from the SD card with the nincfg file deleted. The ISO files are also on the SD card. Do you think it's because of the Nintendont setting that I get a black screen when starting a game?I would first delete any nincfg.bin (I believe that's what it is still called) on the root of the SD card where Nintendont is stored and where you have stored your ISOs as the settings above are NOT default as Memcard Emulation's default is on especially since you are using a Wii U which has no GameCube Memory Card slots and you will not be able to save. Also WiiU Widescreen should be on since you are using a Wii U.
General rule of thumb is to get Nintendont working via Homebrew Channel in vWii mode first as that's gives you the best shot for it to work. Once everything is working then you can experiment with other methods.