Would make sense forwarding these questions to for instance our technical department; I hope when receiving those questions, Airbus, although not answering, took them serious.
I'm not concerned about anything specifically. An Airbus, (and let's not forget the 777, which is all FBW as well!) is a sort of flying nintendo, and even when protected with fuses, a Nintendo turns to toast when blasted with idunnohowmanyvolts.
I think it is interesting to explore all kinds of ways to commit terrorist acts, because, as is succesfully proven on sept 11th, you never know what a terrorist might come up with. And indeed maybe the next terrorist will be having a pacemaker, with a nice little battery, which, when plugged in the electrical net, blows up the avionics.
To that I only want to add: you don't want to present the outcome of such research on the internet. Why give a terrorist all he needs on a silver plate?