Moral of the story: Crap really is "crap". As for your problem, I wish I could help but I don't know how to. You should wait for a user named "mauifrog" to comment, he is very intelligent and will surely be helpful to you.
Instead of installing custom channels that point out to games on a USB (with a higher brick risk), I would set USB Loader GX to channel view and autoboot to it using Priiloader.
Never mess with the system menu, it may prove to be very costly.