Not sure about the wiring. I would assume drilling a hole would screw some things up in there. There's always the option of going through the side of the fridge which isn't glass. Would that work?
I was wondering what you ended up doing with this? I am getting ready to convert mine this week wanted to know if you encountered any issues drilling in the side?
I'd put some tint on the windows, if you plan to have it somewhere visible. That looks ugly as sin being able to see the mess of hoses and kegs. Or, if you live in a frat house, it might blend in.